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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1207.7202 | T. Lappi | T. Lappi | Multigluon correlations in JIMWLK | 4 pages, 3 figures, talk given at the 5th international Conference on
Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard
Probes 2012), May 27th - June 1st, Cagliari (Italy) V2: typo corrections | Nucl. Phys. A 910-911 (2013) 518-521 | 10.1016/j.nuclphysa.2012.12.052 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss applications of the JIMWLK renormalization group equation to
multigluon correlations in high energy collisions. This includes recent
progress in computing the energy dependence of higher point Wilson line
correlators from the JIMWLK renormalization group equation. We find that the
large Nc approximation used so far in the phenomenological literature is not
very accurate. On the other hand a Gaussian finite Nc approximation is
surprisingly close to the full result. We also discuss correlations at large
rapidity separations, relevant for the "ridge" correlations observed in
experiments.
| [
{
"created": "Tue, 31 Jul 2012 09:59:20 GMT",
"version": "v1"
},
{
"created": "Mon, 1 Oct 2012 10:27:03 GMT",
"version": "v2"
}
] | 2013-08-14 | [
[
"Lappi",
"T.",
""
]
] | We discuss applications of the JIMWLK renormalization group equation to multigluon correlations in high energy collisions. This includes recent progress in computing the energy dependence of higher point Wilson line correlators from the JIMWLK renormalization group equation. We find that the large Nc approximation used so far in the phenomenological literature is not very accurate. On the other hand a Gaussian finite Nc approximation is surprisingly close to the full result. We also discuss correlations at large rapidity separations, relevant for the "ridge" correlations observed in experiments. |
0807.3182 | Walton A. Perkins | W. A. Perkins | Pion-Muon Asymmetry Revisited | 9 pages, 3 figures | W. A. Perkins, Int. J. Theor. Phys. 47, 1316 (2008) | 10.1007/s10773-007-9566-0 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Long ago an unexpected and unexplainable phenomena was observed. The
distribution of muons from positive pion decay at rest was anisotropic with an
excess in the backward direction relative to the direction of the proton beam
from which the pions were created. Although this effect was observed by several
different groups with pions produced by different means, the result was not
accepted by the physics community, because it is in direct conflict with a
large set of other experiments indicating that the pion is a pseudoscalar
particle. It is possible to satisfy both sets of experiments if helicity-zero
vector particles exist and the pion is such a particle. Helicity-zero vector
particles have direction but no net spin. For the neutral pion to be a vector
particle requires an additional modification to conventional theory as
discussed herein. An experiment is proposed which can prove that the asymmetry
in the distribution of muons from pion decay is a genuine physical effect
because the asymmetry can be modified in a controllable manner. A positive
result will also prove that the pion is NOT a pseudoscalar particle.
| [
{
"created": "Sun, 20 Jul 2008 20:46:34 GMT",
"version": "v1"
}
] | 2009-11-13 | [
[
"Perkins",
"W. A.",
""
]
] | Long ago an unexpected and unexplainable phenomena was observed. The distribution of muons from positive pion decay at rest was anisotropic with an excess in the backward direction relative to the direction of the proton beam from which the pions were created. Although this effect was observed by several different groups with pions produced by different means, the result was not accepted by the physics community, because it is in direct conflict with a large set of other experiments indicating that the pion is a pseudoscalar particle. It is possible to satisfy both sets of experiments if helicity-zero vector particles exist and the pion is such a particle. Helicity-zero vector particles have direction but no net spin. For the neutral pion to be a vector particle requires an additional modification to conventional theory as discussed herein. An experiment is proposed which can prove that the asymmetry in the distribution of muons from pion decay is a genuine physical effect because the asymmetry can be modified in a controllable manner. A positive result will also prove that the pion is NOT a pseudoscalar particle. |
hep-ph/0011205 | Sukanta Dutta | Debajyoti Choudhury, Sukanta Dutta, Subhendu Rakshit and Saurabh
Rindani | Trilinear Neutral Gauge Boson Couplings | 19 pages, latex, a detailed study of off-shell form-factors included.
To appear in International Journal of Modern Physics, A | Int.J.Mod.Phys. A16 (2001) 4891-4910 | 10.1142/S0217751X01005626 | CUPP-00/4 | hep-ph | null | We study the CP even trilinear neutral gauge boson vertices at one-loop in
the context of the Standard Model and the Minimal Supersymmetric Standard
Model, assuming two of the vector bosons are on-shell. We also study the
changes in the form-factors when these two bosons are off-shell.
| [
{
"created": "Thu, 16 Nov 2000 16:01:48 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Oct 2001 18:11:58 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Choudhury",
"Debajyoti",
""
],
[
"Dutta",
"Sukanta",
""
],
[
"Rakshit",
"Subhendu",
""
],
[
"Rindani",
"Saurabh",
""
]
] | We study the CP even trilinear neutral gauge boson vertices at one-loop in the context of the Standard Model and the Minimal Supersymmetric Standard Model, assuming two of the vector bosons are on-shell. We also study the changes in the form-factors when these two bosons are off-shell. |
hep-ph/0109064 | Guy Moore | Peter Arnold, Guy D. Moore, Laurence G. Yaffe | Photon Emission from Ultrarelativistic Plasmas | 50 pages, 20 figures. Added references and minor rewordings:
published version | JHEP 0111:057,2001 | 10.1088/1126-6708/2001/11/057 | UW/PT 01-21 | hep-ph | null | The emission rate of photons from a hot, weakly coupled ultrarelativistic
plasma is analyzed. Leading-log results, reflecting the sensitivity of the
emission rate to scattering events with momentum transfers from $gT$ to $T$,
have previously been obtained. But a complete leading-order treatment requires
including collinearly enhanced, inelastic processes such as bremsstrahlung.
These inelastic processes receive O(1) modifications from multiple scattering
during the photon emission process, which limits the coherence length of the
emitted radiation (the Landau-Pomeranchuk-Migdal effect). We perform a
diagrammatic analysis to identify, and sum, all leading-order contributions. We
find that the leading-order photon emission rate is not sensitive to
non-perturbative $g^2 T$ scale dynamics. We derive an integral equation for the
photon emission rate which is very similar to the result of Migdal in his
original discussion of the LPM effect. The accurate solution of this integral
equation for specific theories of interest will be reported in a companion
paper.
| [
{
"created": "Fri, 7 Sep 2001 21:00:07 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Dec 2001 18:31:33 GMT",
"version": "v2"
}
] | 2010-02-03 | [
[
"Arnold",
"Peter",
""
],
[
"Moore",
"Guy D.",
""
],
[
"Yaffe",
"Laurence G.",
""
]
] | The emission rate of photons from a hot, weakly coupled ultrarelativistic plasma is analyzed. Leading-log results, reflecting the sensitivity of the emission rate to scattering events with momentum transfers from $gT$ to $T$, have previously been obtained. But a complete leading-order treatment requires including collinearly enhanced, inelastic processes such as bremsstrahlung. These inelastic processes receive O(1) modifications from multiple scattering during the photon emission process, which limits the coherence length of the emitted radiation (the Landau-Pomeranchuk-Migdal effect). We perform a diagrammatic analysis to identify, and sum, all leading-order contributions. We find that the leading-order photon emission rate is not sensitive to non-perturbative $g^2 T$ scale dynamics. We derive an integral equation for the photon emission rate which is very similar to the result of Migdal in his original discussion of the LPM effect. The accurate solution of this integral equation for specific theories of interest will be reported in a companion paper. |
hep-ph/0503228 | C. Hanhart | P. N. Deepak, J. Haidenbauer, and C. Hanhart | Partial-wave analysis of $\vec{p}\vec{p}\to pp\pi^\circ$ data | 14 pages, 11 figures | Phys.Rev. C72 (2005) 024004 | 10.1103/PhysRevC.72.024004 | FZJ-IKP-TH-2005-9 | hep-ph nucl-ex nucl-th | null | We present a partial-wave analysis of the polarization data for the reaction
$\vec{p}\vec{p}\to pp\pi^\circ$, based solely on the recent measurements at
IUCF for this channel. The fit leads to a $\chi^2$ per degree of freedom of
1.7. Methods for an improved analysis are discussed. We compare the extracted
values to those from a meson exchange model.
| [
{
"created": "Wed, 23 Mar 2005 08:05:00 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Deepak",
"P. N.",
""
],
[
"Haidenbauer",
"J.",
""
],
[
"Hanhart",
"C.",
""
]
] | We present a partial-wave analysis of the polarization data for the reaction $\vec{p}\vec{p}\to pp\pi^\circ$, based solely on the recent measurements at IUCF for this channel. The fit leads to a $\chi^2$ per degree of freedom of 1.7. Methods for an improved analysis are discussed. We compare the extracted values to those from a meson exchange model. |
1712.07651 | Laura Tolos | Laura Tolos | The charming beauty of the strong interaction | 10 pages, 6 figures, contribution based on an invited talk at the
FIAS International Symposiom on Discoveries at the Frontiers of Science, June
26-30, 2017, FIAS (Germany) | null | null | null | hep-ph hep-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Charmed and beauty hadrons in matter are discussed within a unitarized
coupled-channel model consistent with heavy-quark spin symmetry. We analyse the
formation of D-mesic states as well as the propagation of charmed and beauty
hadrons in heavy-ion collisions from LHC to FAIR energies.
| [
{
"created": "Thu, 21 Dec 2017 15:05:40 GMT",
"version": "v1"
}
] | 2017-12-22 | [
[
"Tolos",
"Laura",
""
]
] | Charmed and beauty hadrons in matter are discussed within a unitarized coupled-channel model consistent with heavy-quark spin symmetry. We analyse the formation of D-mesic states as well as the propagation of charmed and beauty hadrons in heavy-ion collisions from LHC to FAIR energies. |
1804.08642 | Amin Abou Ibrahim | Amin Aboubrahim and Pran Nath | Supersymmetry at a 28 TeV hadron collider: HE-LHC | 29 pages, 7 figures Accepted for publication in PRD | Phys. Rev. D 98, 015009 (2018) | 10.1103/PhysRevD.98.015009 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The discovery of the Higgs boson at $\sim 125$ GeV indicates that the scale
of weak scale supersymmetry is higher than what was perceived in the pre-Higgs
boson discovery era and lies in the several TeV region. This makes the
discovery of supersymmetry more challenging and argues for hadron colliders
beyond LHC at $\sqrt s=14$ TeV. The Future Circular Collider (FCC) study at
CERN is considering a 100 TeV collider to be installed in a 100 km tunnel in
the Lake Geneva basin. Another 100 km collider being considered in China is the
Super proton-proton Collider (SppC). A third possibility recently proposed is
the High-Energy LHC (HE-LHC) which would use the existing CERN tunnel but
achieve a center-of-mass energy of 28 TeV by using FCC magnet technology at
significantly higher luminosity than at the High Luminosity LHC (HL-LHC). In
this work we investigate the potential of HE-LHC for the discovery of
supersymmetry. We study a class of supergravity unified models under the Higgs
boson mass and the dark matter relic density constraints and compare the
analysis with the potential reach of the HL-LHC. A set of benchmarks are
presented which are beyond the discovery potential of HL-LHC but are
discoverable at HE-LHC. For comparison, we study model points at HE-LHC which
are also discoverable at HL-LHC. For these model points, it is found that their
discovery would require a HL-LHC run between 5-8 years while the same parameter
points can be discovered in a period of few weeks to $\sim 1.5$ yr at HE-LHC
running at its optimal luminosity of $2.5\times 10^{35}$ cm$^{-2}$ s$^{-1}$.
The analysis indicates that the HE-LHC possibility should be seriously pursued
as it would significantly increase the discovery reach for supersymmetry beyond
that of HL-LHC and decrease the run period for discovery.
| [
{
"created": "Mon, 23 Apr 2018 18:05:36 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Jun 2018 14:45:21 GMT",
"version": "v2"
}
] | 2018-07-11 | [
[
"Aboubrahim",
"Amin",
""
],
[
"Nath",
"Pran",
""
]
] | The discovery of the Higgs boson at $\sim 125$ GeV indicates that the scale of weak scale supersymmetry is higher than what was perceived in the pre-Higgs boson discovery era and lies in the several TeV region. This makes the discovery of supersymmetry more challenging and argues for hadron colliders beyond LHC at $\sqrt s=14$ TeV. The Future Circular Collider (FCC) study at CERN is considering a 100 TeV collider to be installed in a 100 km tunnel in the Lake Geneva basin. Another 100 km collider being considered in China is the Super proton-proton Collider (SppC). A third possibility recently proposed is the High-Energy LHC (HE-LHC) which would use the existing CERN tunnel but achieve a center-of-mass energy of 28 TeV by using FCC magnet technology at significantly higher luminosity than at the High Luminosity LHC (HL-LHC). In this work we investigate the potential of HE-LHC for the discovery of supersymmetry. We study a class of supergravity unified models under the Higgs boson mass and the dark matter relic density constraints and compare the analysis with the potential reach of the HL-LHC. A set of benchmarks are presented which are beyond the discovery potential of HL-LHC but are discoverable at HE-LHC. For comparison, we study model points at HE-LHC which are also discoverable at HL-LHC. For these model points, it is found that their discovery would require a HL-LHC run between 5-8 years while the same parameter points can be discovered in a period of few weeks to $\sim 1.5$ yr at HE-LHC running at its optimal luminosity of $2.5\times 10^{35}$ cm$^{-2}$ s$^{-1}$. The analysis indicates that the HE-LHC possibility should be seriously pursued as it would significantly increase the discovery reach for supersymmetry beyond that of HL-LHC and decrease the run period for discovery. |
1202.4014 | Daniel Whiteson | Johan Alwall, Mazin Khader, Arvind Rajaraman, Daniel Whiteson, Michael
Yen | Searching for $Z'$ bosons decaying to gluons | For submission to PRD | Phys. Rev. D 85, 115011 (2012) | 10.1103/PhysRevD.85.115011 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The production and decay of a new heavy vector boson, a chromophilic $Z'$
vector boson, is described. The chromophilic $Z'$ couples only to two gluons,
but its two-body decays are absent, leading to a dominant decay mode of
$Z'\rightarrow q\bar{q}g$. The unusual nature of the interaction predicts a
cross-section which grows with $m_{Z'}$ for a fixed coupling and an
accompanying gluon with a coupling that rises with its energy. We study the
$t\bar{t}g$ decay mode, proposing distinct reconstruction techniques for the
observation of an excess and for the measurement of $m_{Z'}$. We estimate the
sensitivity of current experimental datasets.
| [
{
"created": "Fri, 17 Feb 2012 20:41:58 GMT",
"version": "v1"
}
] | 2012-10-08 | [
[
"Alwall",
"Johan",
""
],
[
"Khader",
"Mazin",
""
],
[
"Rajaraman",
"Arvind",
""
],
[
"Whiteson",
"Daniel",
""
],
[
"Yen",
"Michael",
""
]
] | The production and decay of a new heavy vector boson, a chromophilic $Z'$ vector boson, is described. The chromophilic $Z'$ couples only to two gluons, but its two-body decays are absent, leading to a dominant decay mode of $Z'\rightarrow q\bar{q}g$. The unusual nature of the interaction predicts a cross-section which grows with $m_{Z'}$ for a fixed coupling and an accompanying gluon with a coupling that rises with its energy. We study the $t\bar{t}g$ decay mode, proposing distinct reconstruction techniques for the observation of an excess and for the measurement of $m_{Z'}$. We estimate the sensitivity of current experimental datasets. |
hep-ph/0312003 | Zuo-Tang Liang | Zuo-tang Liang | Spin Alignment of Vector Mesons in Polarized and Unpolarized High Energy
Reactions | Prepared for the proceedings of the X-th International Workshop on
High Energy Spin Physics, JINR Dubna, Sept. 16 - 20, 2003 | null | null | null | hep-ph | null | Recent e+e- annihilation experiments show a striking spin alignment of vector
mesons produced in the fragmentation of a polarized quark.We show that these
data imply a simple relation between the polarization of the anti-quark, which
is produced in the fragmentation process to combine with the fragmenting quark
to form the meson, and that of the fragmenting quark. After having obtained a
good fit to the e+e- data, we extend the calculations to lepton-nucleon and
nucleon-nucleon collisions with polarized beams. We also discuss the relation
between the spin alignment of vector meson in unpolarized hadron-hadron
collisions and the single-spin left-right asymmetry. We make predictions for
the polarization of the vector mesons in these reactions which can be checked
by future experiments.
| [
{
"created": "Sat, 29 Nov 2003 06:49:53 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Liang",
"Zuo-tang",
""
]
] | Recent e+e- annihilation experiments show a striking spin alignment of vector mesons produced in the fragmentation of a polarized quark.We show that these data imply a simple relation between the polarization of the anti-quark, which is produced in the fragmentation process to combine with the fragmenting quark to form the meson, and that of the fragmenting quark. After having obtained a good fit to the e+e- data, we extend the calculations to lepton-nucleon and nucleon-nucleon collisions with polarized beams. We also discuss the relation between the spin alignment of vector meson in unpolarized hadron-hadron collisions and the single-spin left-right asymmetry. We make predictions for the polarization of the vector mesons in these reactions which can be checked by future experiments. |
hep-ph/9905330 | Dmitri Kazakov | D.I.Kazakov | The Higgs Boson: Shall We See It Soon Or Is It Still Far Away? | 13 pages, LaTex, 4 ps figures, Submitted to special issue of
Phys.Reports dedicated to 70th birthday of L.B.Okun | Phys.Rept.320:187-198,1999 | 10.1016/S0370-1573(99)00068-X | null | hep-ph | null | The status of the Higgs boson mass in the Standard Model and its
supersymmetric extensions is reviewed and the perspectives of Higgs searches
are discussed. The parameter space of the Minimal Supersymmetric Standard Model
(MSSM) is analysed with the emphasis on the lightest Higgs mass. The infrared
behaviour of renormalization group equations for the parameters of MSSM is
examined and infrared quasi-fixed points are used for the Higgs mass
predictions. They strongly suggest the Higgs mass to be lighter than 100 or 130
GeV for low and high $\tan\beta$ scenarios, respectively. Extended models,
however, allow one to increase these limits for low $\tan\beta$ up to 50%.
| [
{
"created": "Thu, 13 May 1999 16:19:12 GMT",
"version": "v1"
}
] | 2009-11-19 | [
[
"Kazakov",
"D. I.",
""
]
] | The status of the Higgs boson mass in the Standard Model and its supersymmetric extensions is reviewed and the perspectives of Higgs searches are discussed. The parameter space of the Minimal Supersymmetric Standard Model (MSSM) is analysed with the emphasis on the lightest Higgs mass. The infrared behaviour of renormalization group equations for the parameters of MSSM is examined and infrared quasi-fixed points are used for the Higgs mass predictions. They strongly suggest the Higgs mass to be lighter than 100 or 130 GeV for low and high $\tan\beta$ scenarios, respectively. Extended models, however, allow one to increase these limits for low $\tan\beta$ up to 50%. |
hep-ph/0111403 | Ismd31 | Liang Zuo-tang | Hadronization mechanisms and spin effects in high energy fragmentation
processes | 6 pages, 3 figures (in eps) talk given at XXXI International
Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China URL
http://ismd31.ccnu.edu.cn/ | null | null | null | hep-ph | null | Spin effects in high energy fragmentation processes can provide us with
important information on hadronization mechanisms and spin structure of
hadrons. It can in particular give new tests to the hadronization models. In
this talk, we make a brief introduction to the different topics studied in this
connection and a short summary of the available data. After that, we present a
short summary of the main theoretical results we obtained in studying these
different topics. The talk was mainly based on the publications [4-8] which
have been finished in collaboration with C.Boros, Liu Chun-xiu and Xu Qing-hua.
| [
{
"created": "Thu, 29 Nov 2001 11:22:58 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Zuo-tang",
"Liang",
""
]
] | Spin effects in high energy fragmentation processes can provide us with important information on hadronization mechanisms and spin structure of hadrons. It can in particular give new tests to the hadronization models. In this talk, we make a brief introduction to the different topics studied in this connection and a short summary of the available data. After that, we present a short summary of the main theoretical results we obtained in studying these different topics. The talk was mainly based on the publications [4-8] which have been finished in collaboration with C.Boros, Liu Chun-xiu and Xu Qing-hua. |
1706.03070 | Javi Serra | Brando Bellazzini, Francesco Riva, Javi Serra and Francesco Sgarlata | The Other Fermion Compositeness | 32 pages on how Thomson might have discovered supersymmetry; v2: few
typos fixed and comments added | JHEP 1711 (2017) 020 | 10.1007/JHEP11(2017)020 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss the only two viable realizations of fermion compositeness
described by a calculable relativistic effective field theory consistent with
unitarity, crossing symmetry and analyticity: chiral-compositeness vs
goldstino-compositeness. We construct the effective theory of $\mathcal{N}$
Goldstini and show how the Standard Model can emerge from this dynamics. We
present new bounds on either type of compositeness, for quarks and leptons,
using dilepton searches at LEP, dijets at the LHC, as well as low-energy
observables and precision measurements. Remarkably, a scale of compositeness
for Goldstino-like electrons in the 2 TeV range is compatible with present
data, and so are Goldstino-like first generation quarks with a compositeness
scale in the 10 TeV range. Moreover, assuming maximal $R$-symmetry,
goldstino-compositeness of both right- and left-handed quarks predicts exotic
spin-1/2 colored sextet particles that are potentially within the reach of the
LHC.
| [
{
"created": "Fri, 9 Jun 2017 18:00:01 GMT",
"version": "v1"
},
{
"created": "Mon, 13 Nov 2017 13:18:38 GMT",
"version": "v2"
}
] | 2017-12-06 | [
[
"Bellazzini",
"Brando",
""
],
[
"Riva",
"Francesco",
""
],
[
"Serra",
"Javi",
""
],
[
"Sgarlata",
"Francesco",
""
]
] | We discuss the only two viable realizations of fermion compositeness described by a calculable relativistic effective field theory consistent with unitarity, crossing symmetry and analyticity: chiral-compositeness vs goldstino-compositeness. We construct the effective theory of $\mathcal{N}$ Goldstini and show how the Standard Model can emerge from this dynamics. We present new bounds on either type of compositeness, for quarks and leptons, using dilepton searches at LEP, dijets at the LHC, as well as low-energy observables and precision measurements. Remarkably, a scale of compositeness for Goldstino-like electrons in the 2 TeV range is compatible with present data, and so are Goldstino-like first generation quarks with a compositeness scale in the 10 TeV range. Moreover, assuming maximal $R$-symmetry, goldstino-compositeness of both right- and left-handed quarks predicts exotic spin-1/2 colored sextet particles that are potentially within the reach of the LHC. |
hep-ph/0701183 | Marco Radici | Marco Radici | Transversity and inclusive two-pion production | 4 pages, 4 composite figures, talk presented at the 17th
International Spin Physics Symposium (SPIN2006), Kyoto (Japan), October 2-7,
2006 | AIPConf.Proc.915:654-657,2007 | 10.1063/1.2750865 | null | hep-ph | null | A model for dihadron fragmentation functions is briefly outlined, that
describes the fragmentation of a quark in two unpolarized hadrons. The
parameters are tuned to the output of the PYTHIA event generator for two-hadron
semi-inclusive production in deep inelastic scattering at HERMES. Then,
predictions are made for the unknown polarized fragmentation function and the
related single-spin asymmetry in the azimuthal distribution of $\pi^+ \pi^-$
pairs in semi-inclusive deep inelastic scattering on transversely polarized
targets at HERMES and COMPASS. This asymmetry can be used to extract the quark
transversity distribution.
| [
{
"created": "Mon, 22 Jan 2007 17:34:33 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Radici",
"Marco",
""
]
] | A model for dihadron fragmentation functions is briefly outlined, that describes the fragmentation of a quark in two unpolarized hadrons. The parameters are tuned to the output of the PYTHIA event generator for two-hadron semi-inclusive production in deep inelastic scattering at HERMES. Then, predictions are made for the unknown polarized fragmentation function and the related single-spin asymmetry in the azimuthal distribution of $\pi^+ \pi^-$ pairs in semi-inclusive deep inelastic scattering on transversely polarized targets at HERMES and COMPASS. This asymmetry can be used to extract the quark transversity distribution. |
hep-ph/9705423 | Valera Lyubovitskij | M. A. Ivanov (JINR, Dubna) and V. E. Lyubovitskij (JINR, Dubna and
Tomsk University) | The gamma(*) pi(0) -> gamma form factor | 7 pages, LaTeX-file (elsart.sty), 2 Postscript figures | Phys.Lett. B408 (1997) 435-438 | 10.1016/S0370-2693(97)00776-4 | null | hep-ph | null | The gamma(*) pi(0) -> gamma form factor is obtained within the Lagrangian
quark model with separable interaction known to provide a good description of
the pion observables at low energies. The pion-quarks vertex is chosen in a
Gaussian form. The form factor obtained is close to the available experimental
data and reaches smoothly the Brodsky-Lepage limit at Q2 = 10 GeV2.
| [
{
"created": "Mon, 26 May 1997 12:37:06 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Ivanov",
"M. A.",
"",
"JINR, Dubna"
],
[
"Lyubovitskij",
"V. E.",
"",
"JINR, Dubna and\n Tomsk University"
]
] | The gamma(*) pi(0) -> gamma form factor is obtained within the Lagrangian quark model with separable interaction known to provide a good description of the pion observables at low energies. The pion-quarks vertex is chosen in a Gaussian form. The form factor obtained is close to the available experimental data and reaches smoothly the Brodsky-Lepage limit at Q2 = 10 GeV2. |
1510.02235 | Narayan Rana | Taushif Ahmed, M. C. Kumar, Prakash Mathews, Narayan Rana and V.
Ravindran | Pseudo-scalar Higgs Boson Production at Threshold N$^3$LO and N$^3$LL
QCD | 34 pages, 17 figures | null | 10.1140/epjc/s10052-016-4199-1 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the first results on the production of pseudo-scalar through gluon
fusion at the LHC to N$^3$LO in QCD taking into account only soft gluon
effects. We have used the effective Lagrangian that describes the coupling of
pseudo-scalar with the gluons in the large top quark mass limit. We have used
recently available quantities namely the three loop pseudo-scalar form factor
and the third order universal soft function in QCD to achieve this. Along with
the fixed order results, we also present the process dependent resummation
coefficient for threshold resummation to N$^3$LL in QCD. Phenomenological
impact of these threshold N$^3$LO corrections to pseudo-scalar production at
the LHC is presented and their role to reduce the renormalisation scale
dependence is demonstrated.
| [
{
"created": "Thu, 8 Oct 2015 08:43:28 GMT",
"version": "v1"
}
] | 2016-07-20 | [
[
"Ahmed",
"Taushif",
""
],
[
"Kumar",
"M. C.",
""
],
[
"Mathews",
"Prakash",
""
],
[
"Rana",
"Narayan",
""
],
[
"Ravindran",
"V.",
""
]
] | We present the first results on the production of pseudo-scalar through gluon fusion at the LHC to N$^3$LO in QCD taking into account only soft gluon effects. We have used the effective Lagrangian that describes the coupling of pseudo-scalar with the gluons in the large top quark mass limit. We have used recently available quantities namely the three loop pseudo-scalar form factor and the third order universal soft function in QCD to achieve this. Along with the fixed order results, we also present the process dependent resummation coefficient for threshold resummation to N$^3$LL in QCD. Phenomenological impact of these threshold N$^3$LO corrections to pseudo-scalar production at the LHC is presented and their role to reduce the renormalisation scale dependence is demonstrated. |
1902.05126 | Vadim Guzey | V. Guzey (Jyvaskyla U., Helsinki U., St. Petersburg, INP), M. Klasen
(Munster U., ITP) | Constraints on nuclear parton distributions from dijet photoproduction
at the LHC | 16 pages, 11 figures. Final published version | null | 10.1140/epjc/s10052-019-6905-2 | MS-TP-19-03 | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using QCD calculations of the cross section of inclusive dijet
photoproduction in Pb-Pb ultraperipheral collisions in the LHC kinematics as
pseudo-data, we study the effect of including these data using the Bayesian
reweighting technique on nCTEQ15, nCTEQ15np, and EPPS16 nuclear parton
distribution functions (nPDFs). We find that, depending on the assumed error of
the pseudo-data, it leads to a significant reduction of the nPDF uncertainties
at small values of the momentum fraction $x_A$. Taking the error to be 5\%, the
uncertainty of nCTEQ15 and nCTEQ15np nPDFs reduces approximately by a factor of
two at $x_A=10^{-3}$. At the same time, the reweighting effect on EPPS16 nPDFs
is much smaller due to the higher value of the tolerance and a more flexible
parametrization form.
| [
{
"created": "Wed, 13 Feb 2019 20:49:55 GMT",
"version": "v1"
},
{
"created": "Tue, 14 May 2019 09:05:43 GMT",
"version": "v2"
}
] | 2019-05-22 | [
[
"Guzey",
"V.",
"",
"Jyvaskyla U., Helsinki U., St. Petersburg, INP"
],
[
"Klasen",
"M.",
"",
"Munster U., ITP"
]
] | Using QCD calculations of the cross section of inclusive dijet photoproduction in Pb-Pb ultraperipheral collisions in the LHC kinematics as pseudo-data, we study the effect of including these data using the Bayesian reweighting technique on nCTEQ15, nCTEQ15np, and EPPS16 nuclear parton distribution functions (nPDFs). We find that, depending on the assumed error of the pseudo-data, it leads to a significant reduction of the nPDF uncertainties at small values of the momentum fraction $x_A$. Taking the error to be 5\%, the uncertainty of nCTEQ15 and nCTEQ15np nPDFs reduces approximately by a factor of two at $x_A=10^{-3}$. At the same time, the reweighting effect on EPPS16 nPDFs is much smaller due to the higher value of the tolerance and a more flexible parametrization form. |
hep-ph/0703275 | Wan-Il Park | Gary N. Felder, Hyunbyuk Kim, Wan-Il Park and Ewan D. Stewart | Preheating and Affleck-Dine leptogenesis after thermal inflation | 38 pages, 17 figures | JCAP 0706:005,2007 | 10.1088/1475-7516/2007/06/005 | KAIST-TH 2007/03 | hep-ph | null | Previously, we proposed a model of low energy Affleck-Dine leptogenesis in
the context of thermal inflation. The lepton asymmetry is generated at the end
of thermal inflation, which occurs at a relatively low energy scale with the
Hubble parameter somewhere in the range $1 \keV \lesssim H \lesssim 1 \MeV$.
Thus Hubble damping will be ineffective in bringing the Affleck-Dine field into
the lepton conserving region near the origin, leaving the possibility that the
lepton number could be washed out. Previously, we suggested that preheating
could damp the amplitude of the Affleck-Dine field allowing conservation of the
lepton number. In this paper, we demonstrate numerically that preheating does
efficiently damp the amplitude of the Affleck-Dine field and that the lepton
number is conserved as the result. In addition to demonstrating a crucial
aspect of our model, it also opens the more general possibility of low energy
Affleck-Dine baryogenesis.
| [
{
"created": "Mon, 26 Mar 2007 15:36:35 GMT",
"version": "v1"
}
] | 2010-10-27 | [
[
"Felder",
"Gary N.",
""
],
[
"Kim",
"Hyunbyuk",
""
],
[
"Park",
"Wan-Il",
""
],
[
"Stewart",
"Ewan D.",
""
]
] | Previously, we proposed a model of low energy Affleck-Dine leptogenesis in the context of thermal inflation. The lepton asymmetry is generated at the end of thermal inflation, which occurs at a relatively low energy scale with the Hubble parameter somewhere in the range $1 \keV \lesssim H \lesssim 1 \MeV$. Thus Hubble damping will be ineffective in bringing the Affleck-Dine field into the lepton conserving region near the origin, leaving the possibility that the lepton number could be washed out. Previously, we suggested that preheating could damp the amplitude of the Affleck-Dine field allowing conservation of the lepton number. In this paper, we demonstrate numerically that preheating does efficiently damp the amplitude of the Affleck-Dine field and that the lepton number is conserved as the result. In addition to demonstrating a crucial aspect of our model, it also opens the more general possibility of low energy Affleck-Dine baryogenesis. |
hep-ph/0410140 | Hitoshi Murayama | Hitoshi Murayama | Alternatives to Seesaw | Talk at Fujihara Seminar On Neutrino Mass And Seesaw Mechanism
(SEESAW 1979-2004), 23-25 Feb 2004, KEK. 14 pages, uses espcrc2.sty | Nucl.Phys.Proc.Suppl.137:206-219,2004 | 10.1016/j.nuclphysbps.2004.10.071 | null | hep-ph | null | The seesaw mechanism is attractive not only because it "explains'' small
neutrino mass, but also because of its packaging with the SUSY-GUT,
leptogenesis, Dark Matter, and electroweak symmetry breaking. However, this
package has the flavor, CP, and gravitino problems. I discuss two alternatives
to the seesaw mechanism. In one of them, the anomaly-mediated supersymmetry
breaking solves these problems, while predicts naturally light Dirac neutrinos.
In the other, the light Majorana neutrinos arise from supersymmetry breaking
with right-handed neutrinos below TeV, and the Dark Matter and collider
phenomenology are significantly different.
| [
{
"created": "Sun, 10 Oct 2004 06:43:18 GMT",
"version": "v1"
}
] | 2009-09-29 | [
[
"Murayama",
"Hitoshi",
""
]
] | The seesaw mechanism is attractive not only because it "explains'' small neutrino mass, but also because of its packaging with the SUSY-GUT, leptogenesis, Dark Matter, and electroweak symmetry breaking. However, this package has the flavor, CP, and gravitino problems. I discuss two alternatives to the seesaw mechanism. In one of them, the anomaly-mediated supersymmetry breaking solves these problems, while predicts naturally light Dirac neutrinos. In the other, the light Majorana neutrinos arise from supersymmetry breaking with right-handed neutrinos below TeV, and the Dark Matter and collider phenomenology are significantly different. |
hep-ph/9803501 | Patricia Ball | Patricia Ball | B decays into light mesons | 8 pages latex plus one figure; invited talk at Moriond QCD 98 | null | null | FERMILAB-CONF-98/098-T | hep-ph | null | I calculate the form factors describing semileptonic and penguin induced
decays of B mesons into light pseudoscalar and vector mesons. The form factors
are calculated from QCD sum rules on the light-cone including contributions up
to twist 4, radiative corrections to the leading twist contribution and SU(3)
breaking effects. The theoretical uncertainty is estimated to be $\sim$
(15-20)%.
| [
{
"created": "Tue, 31 Mar 1998 20:45:05 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ball",
"Patricia",
""
]
] | I calculate the form factors describing semileptonic and penguin induced decays of B mesons into light pseudoscalar and vector mesons. The form factors are calculated from QCD sum rules on the light-cone including contributions up to twist 4, radiative corrections to the leading twist contribution and SU(3) breaking effects. The theoretical uncertainty is estimated to be $\sim$ (15-20)%. |
1810.07019 | Danning Li | Jianwei Chen, Song He, Mei Huang, Danning Li | Critical exponents of finite temperature chiral phase transition in
soft-wall AdS/QCD models | 32 pages, 11 figures, regular article | null | 10.1007/JHEP01(2019)165 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Criticality of chiral phase transition at finite temperature is investigated
in a soft-wall AdS/QCD model with $SU_L(N_f)\times SU_R(N_f)$ symmetry,
especially for $N_f=2,3$ and $N_f=2+1$. It is shown that in quark mass
plane($m_{u/d}-m_s$) chiral phase transition is second order at a certain
critical line, by which the whole plane is divided into first order and
crossover regions. The critical exponents $\beta$ and $\delta$, describing
critical behavior of chiral condensate along temperature axis and light quark
mass axis, are extracted both numerically and analytically. The model gives the
critical exponents of the values $\beta=\frac{1}{2}, \delta=3$ and
$\beta=\frac{1}{3}, \delta=3$ for $N_f=2$ and $N_f=3$ respectively. For
$N_f=2+1$, in small strange quark mass($m_s$) region, the phase transitions for
strange quark and $u/d$ quarks are strongly coupled, and the critical exponents
are $\beta=\frac{1}{3},\delta=3$; when $m_s$ is larger than
$m_{s,t}=0.290\rm{GeV}$, the dynamics of light flavors($u,d$) and strange
quarks decoupled and the critical exponents for $\bar{u}u$ and $\bar{d}d$
becomes $\beta=\frac{1}{2},\delta=3$, exactly the same as $N_f=2$ result and
the mean field result of 3D Ising model; between the two segments, there is a
tri-critical point at $m_{s,t}=0.290\rm{GeV}$, at which
$\beta=0.250,\delta=4.975$. In some sense, the current results is still at mean
field level, and we also showed the possibility to go beyond mean field
approximation by including the higher power of scalar potential and the
temperature dependence of dilaton field, which might be reasonable in a full
back-reaction model. The current study might also provide reasonable
constraints on constructing a realistic holographic QCD model, which could
describe both chiral dynamics and glue-dynamics correctly.
| [
{
"created": "Tue, 16 Oct 2018 14:18:58 GMT",
"version": "v1"
}
] | 2019-02-20 | [
[
"Chen",
"Jianwei",
""
],
[
"He",
"Song",
""
],
[
"Huang",
"Mei",
""
],
[
"Li",
"Danning",
""
]
] | Criticality of chiral phase transition at finite temperature is investigated in a soft-wall AdS/QCD model with $SU_L(N_f)\times SU_R(N_f)$ symmetry, especially for $N_f=2,3$ and $N_f=2+1$. It is shown that in quark mass plane($m_{u/d}-m_s$) chiral phase transition is second order at a certain critical line, by which the whole plane is divided into first order and crossover regions. The critical exponents $\beta$ and $\delta$, describing critical behavior of chiral condensate along temperature axis and light quark mass axis, are extracted both numerically and analytically. The model gives the critical exponents of the values $\beta=\frac{1}{2}, \delta=3$ and $\beta=\frac{1}{3}, \delta=3$ for $N_f=2$ and $N_f=3$ respectively. For $N_f=2+1$, in small strange quark mass($m_s$) region, the phase transitions for strange quark and $u/d$ quarks are strongly coupled, and the critical exponents are $\beta=\frac{1}{3},\delta=3$; when $m_s$ is larger than $m_{s,t}=0.290\rm{GeV}$, the dynamics of light flavors($u,d$) and strange quarks decoupled and the critical exponents for $\bar{u}u$ and $\bar{d}d$ becomes $\beta=\frac{1}{2},\delta=3$, exactly the same as $N_f=2$ result and the mean field result of 3D Ising model; between the two segments, there is a tri-critical point at $m_{s,t}=0.290\rm{GeV}$, at which $\beta=0.250,\delta=4.975$. In some sense, the current results is still at mean field level, and we also showed the possibility to go beyond mean field approximation by including the higher power of scalar potential and the temperature dependence of dilaton field, which might be reasonable in a full back-reaction model. The current study might also provide reasonable constraints on constructing a realistic holographic QCD model, which could describe both chiral dynamics and glue-dynamics correctly. |
2311.17220 | Manish Sharma Mr. | Manish Kumar Sharma, Saumyen Kundu, Prasanta Kumar Das | Exploring the Electromagnetically Interacting Dark Matter at the
International Linear Collider | 8 pages, 5 figures, 3 tables | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Dark Matter being electrically neutral does not participate in
electromagnetic interactions at leading order. However, we discuss here
fermionic dark matter (DM) with permanent magnetic and electric dipole moment
that interacts electromagnetically with photon at loop-level through a
dimension-5 operator. We discuss the search prospect of the dark matter at the
proposed International Linear Collider (ILC) and constrain the parameter space
in the plane of the DM mass and the cutoff scale $\Lambda$. At the 500 GeV ILC
with $4$ ab$^{-1}$ of integrated luminosity we probed the mono-photon channel
and utilizing the advantages of beam polarization we obtained an upper bound on
the cutoff scale that reaches up to $\Lambda = 3.72$ TeV.
| [
{
"created": "Tue, 28 Nov 2023 20:45:32 GMT",
"version": "v1"
}
] | 2023-11-30 | [
[
"Sharma",
"Manish Kumar",
""
],
[
"Kundu",
"Saumyen",
""
],
[
"Das",
"Prasanta Kumar",
""
]
] | Dark Matter being electrically neutral does not participate in electromagnetic interactions at leading order. However, we discuss here fermionic dark matter (DM) with permanent magnetic and electric dipole moment that interacts electromagnetically with photon at loop-level through a dimension-5 operator. We discuss the search prospect of the dark matter at the proposed International Linear Collider (ILC) and constrain the parameter space in the plane of the DM mass and the cutoff scale $\Lambda$. At the 500 GeV ILC with $4$ ab$^{-1}$ of integrated luminosity we probed the mono-photon channel and utilizing the advantages of beam polarization we obtained an upper bound on the cutoff scale that reaches up to $\Lambda = 3.72$ TeV. |
1502.02214 | Mohammad Athar SAJJAD | M. Rafi Alam, I. Ruiz Simo, L. Alvarez-Ruso, M. Sajjad Athar and M. J.
Vicente Vacas | Weak Production of Strange Particles and $\eta$ Mesons off the Nucleon | To appear in AIP Conf. Proc. of the Workshop CETUP*14, 12 Pages, 13
Figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The strange particle production induced by (anti)neutrino off nucleon has
been studied for $|\Delta S|=0$ and $|\Delta S|=1$ channels.
The reactions those we have considered are for the production of single
kaon/antikaon, eta and associated particle production processes.
We have developed a microscopical model based on the SU(3) chiral Lagrangian.
The basic parameters of the model are $f_\pi$, the pion decay constant, Cabibbo
angle, the proton and neutron magnetic moments and the axial vector coupling
constants for the baryons octet. For antikaon production we have also included
$\Sigma^*$(1385) resonance and for eta production $S_{11}$(1535) and
$S_{11}$(1650) resonances are included.
| [
{
"created": "Sun, 8 Feb 2015 06:12:40 GMT",
"version": "v1"
}
] | 2015-02-10 | [
[
"Alam",
"M. Rafi",
""
],
[
"Simo",
"I. Ruiz",
""
],
[
"Alvarez-Ruso",
"L.",
""
],
[
"Athar",
"M. Sajjad",
""
],
[
"Vacas",
"M. J. Vicente",
""
]
] | The strange particle production induced by (anti)neutrino off nucleon has been studied for $|\Delta S|=0$ and $|\Delta S|=1$ channels. The reactions those we have considered are for the production of single kaon/antikaon, eta and associated particle production processes. We have developed a microscopical model based on the SU(3) chiral Lagrangian. The basic parameters of the model are $f_\pi$, the pion decay constant, Cabibbo angle, the proton and neutron magnetic moments and the axial vector coupling constants for the baryons octet. For antikaon production we have also included $\Sigma^*$(1385) resonance and for eta production $S_{11}$(1535) and $S_{11}$(1650) resonances are included. |
1512.08441 | Qing-Hong Cao | Qing-Hong Cao, Yandong Liu, Ke-Pan Xie, Bin Yan, Dong-Ming Zhang | The Diphoton Excess, Low Energy Theorem and the 331 Model | To appear in PRD | Phys. Rev. D 93, 075030 (2016) | 10.1103/PhysRevD.93.075030 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We interpret the diphoton anomaly as a heavy scalar $H_3$ in the so-called
331 model. The scalar is responsible for breaking the $SU(3)_C\otimes
SU(3)_L\otimes U(1)_X$ gauge symmetry down to the standard model electroweak
gauge group. It mainly couples to the standard model gluons and photons through
quantum loops involving heavy quarks and leptons. Those quarks and leptons, in
together with the SM quarks and leptons, form the fundamental representation of
the 331 model. We use low energy theorem to calculate effective coupling of
$H_3gg$, $H_3\gamma\gamma$, $H_3ZZ$, $H_3WW$ and $H_3Z\gamma$. The analytical
results can be applied to new physics models satisfying the low energy theorem.
We show that the heavy quark and lepton contribution cannot produce enough
diphoton pairs. It is crucial to include the contribution of charged scalars to
explain the diphoton excess. The extra neutral $Z^\prime$ boson could also
explain the 2 TeV diboson excess observed at the LHC Run-I.
| [
{
"created": "Mon, 28 Dec 2015 16:16:20 GMT",
"version": "v1"
},
{
"created": "Fri, 8 Jan 2016 08:01:38 GMT",
"version": "v2"
},
{
"created": "Tue, 19 Apr 2016 12:11:45 GMT",
"version": "v3"
}
] | 2016-04-27 | [
[
"Cao",
"Qing-Hong",
""
],
[
"Liu",
"Yandong",
""
],
[
"Xie",
"Ke-Pan",
""
],
[
"Yan",
"Bin",
""
],
[
"Zhang",
"Dong-Ming",
""
]
] | We interpret the diphoton anomaly as a heavy scalar $H_3$ in the so-called 331 model. The scalar is responsible for breaking the $SU(3)_C\otimes SU(3)_L\otimes U(1)_X$ gauge symmetry down to the standard model electroweak gauge group. It mainly couples to the standard model gluons and photons through quantum loops involving heavy quarks and leptons. Those quarks and leptons, in together with the SM quarks and leptons, form the fundamental representation of the 331 model. We use low energy theorem to calculate effective coupling of $H_3gg$, $H_3\gamma\gamma$, $H_3ZZ$, $H_3WW$ and $H_3Z\gamma$. The analytical results can be applied to new physics models satisfying the low energy theorem. We show that the heavy quark and lepton contribution cannot produce enough diphoton pairs. It is crucial to include the contribution of charged scalars to explain the diphoton excess. The extra neutral $Z^\prime$ boson could also explain the 2 TeV diboson excess observed at the LHC Run-I. |
1406.2167 | Ekaterina Christova | S.M.Bilenky and E. Christova | The axial form factor and polarization of the final nucleon in
quasi-elastic \nu-N scattering | 4 pages with 4 figures; a talk given at XV Workshop on High Energy
Spin Physics in Dubna, Russia, October 8-12, 2013 (DSPIN 2013) | null | null | null | hep-ph | http://creativecommons.org/licenses/by/3.0/ | We have calculated the polarization of the final nucleon in charged current
quasi-elastic \nu -N scattering. We show that the longitudinal and transverse
polarizations, as well as their ratio exhibit simple dependence on the axial
form factor and their sensitivity to the axial mass is much stronger than that
of the cross section. This suggests that measurements of the polarization of
the nucleon in the high-statistics neutrino experiments could provide important
information on the axial form factor.
| [
{
"created": "Mon, 9 Jun 2014 13:10:22 GMT",
"version": "v1"
}
] | 2014-06-10 | [
[
"Bilenky",
"S. M.",
""
],
[
"Christova",
"E.",
""
]
] | We have calculated the polarization of the final nucleon in charged current quasi-elastic \nu -N scattering. We show that the longitudinal and transverse polarizations, as well as their ratio exhibit simple dependence on the axial form factor and their sensitivity to the axial mass is much stronger than that of the cross section. This suggests that measurements of the polarization of the nucleon in the high-statistics neutrino experiments could provide important information on the axial form factor. |
hep-ph/9707407 | Arthur Halprin | A. Halprin (1) and C.N. Leung (1 and 2) ((1) University of Delaware,
Newark, Delaware, USA (2)A cademia Sinica, Taipei, Taiwan) | Neutrino Oscillations from String Theory | 7 pages LaTEX | Phys.Lett.B416:361-364,1998 | 10.1016/S0370-2693(97)01254-9 | UDEHEP-07-97 | hep-ph | null | We derive the character of neutrino oscillations that results from a model of
equivalence principle violation suggested recently by Damour and Polyakov as a
plausible consequence of string theory. In this model neutrino oscillations
will take place through interaction with a long range scalar field of
gravitational origin even if the neutrinos are degenerate in mass. The energy
dependence of the oscillation length is identical to that in the conventional
mass mixing mechanism. This possibility further highlghts the independence of
and need for more exacting direct neutrino mass measurements together with a
next generation of neutrinoless double beta decay experiments.
| [
{
"created": "Mon, 21 Jul 1997 17:18:39 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Halprin",
"A.",
"",
"1 and 2"
],
[
"Leung",
"C. N.",
"",
"1 and 2"
]
] | We derive the character of neutrino oscillations that results from a model of equivalence principle violation suggested recently by Damour and Polyakov as a plausible consequence of string theory. In this model neutrino oscillations will take place through interaction with a long range scalar field of gravitational origin even if the neutrinos are degenerate in mass. The energy dependence of the oscillation length is identical to that in the conventional mass mixing mechanism. This possibility further highlghts the independence of and need for more exacting direct neutrino mass measurements together with a next generation of neutrinoless double beta decay experiments. |
2311.01667 | Stephan Meighen-Berger | Stephan A. Meighen-Berger, John F. Beacom, Nicole F. Bell, Matthew J.
Dolan | New Signal of Atmospheric Tau Neutrino Appearance: Sub-GeV
Neutral-Current Interactions in JUNO | 12 pages, 8 figures | null | null | null | hep-ph astro-ph.HE hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose the first practical method to detect atmospheric tau neutrino
appearance at sub-GeV energies, which would be an important test of $\nu_\mu
\rightarrow \nu_\tau$ oscillations and of new-physics scenarios. In the
Jiangmen Underground Neutrino Observatory (JUNO; starts in 2024), active-flavor
neutrinos eject neutrons from carbon via neutral-current quasielastic
scattering. This produces a two-part signal: the prompt part is caused by the
scattering of the neutron in the scintillator, and the delayed part by its
radiative capture. Such events have been observed in KamLAND, but only in small
numbers and were treated as a background. With $\nu_\mu \rightarrow \nu_\tau$
oscillations, JUNO should measure a clean sample of 55 events/yr; with simple
$\nu_\mu$ disappearance, this would instead be 41 events/yr, where the latter
is determined from Super-Kamiokande charged-current measurements at similar
neutrino energies. Implementing this method will require precise laboratory
measurements of neutrino-nucleus cross sections or other developments. With
those, JUNO will have $5\sigma$ sensitivity to tau-neutrino appearance in 5
years exposure, and likely sooner.
| [
{
"created": "Fri, 3 Nov 2023 02:05:20 GMT",
"version": "v1"
}
] | 2023-11-13 | [
[
"Meighen-Berger",
"Stephan A.",
""
],
[
"Beacom",
"John F.",
""
],
[
"Bell",
"Nicole F.",
""
],
[
"Dolan",
"Matthew J.",
""
]
] | We propose the first practical method to detect atmospheric tau neutrino appearance at sub-GeV energies, which would be an important test of $\nu_\mu \rightarrow \nu_\tau$ oscillations and of new-physics scenarios. In the Jiangmen Underground Neutrino Observatory (JUNO; starts in 2024), active-flavor neutrinos eject neutrons from carbon via neutral-current quasielastic scattering. This produces a two-part signal: the prompt part is caused by the scattering of the neutron in the scintillator, and the delayed part by its radiative capture. Such events have been observed in KamLAND, but only in small numbers and were treated as a background. With $\nu_\mu \rightarrow \nu_\tau$ oscillations, JUNO should measure a clean sample of 55 events/yr; with simple $\nu_\mu$ disappearance, this would instead be 41 events/yr, where the latter is determined from Super-Kamiokande charged-current measurements at similar neutrino energies. Implementing this method will require precise laboratory measurements of neutrino-nucleus cross sections or other developments. With those, JUNO will have $5\sigma$ sensitivity to tau-neutrino appearance in 5 years exposure, and likely sooner. |
hep-ph/0406024 | Tomoaki Nagasawa | Tomoaki Nagasawa and Makoto Sakamoto | Higgsless Gauge Symmetry Breaking with a Large Mass Hierarchy | 9 pages, 1 figure, PTPTeX | Prog.Theor.Phys.112:629-638,2004 | 10.1143/PTP.112.629 | KOBE-TH-04-04 | hep-ph hep-th | null | We propose a mechanism of Higgsless gauge symmetry breaking with a large mass
hierarchy. We consider a 5D gauge theory on an orbifold $S^1/Z_2$. The gauge
symmetry is broken by orbifolding and also nontrivial boundary conditions at
fixed points. All 4D modes which survive at low energies are found to be
localized around fixed points. Supersymmetry plays an important role in our
mechanism. The tree-level unitarity in our model is briefly discussed.
| [
{
"created": "Wed, 2 Jun 2004 08:59:24 GMT",
"version": "v1"
},
{
"created": "Wed, 11 Aug 2004 02:10:56 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Nagasawa",
"Tomoaki",
""
],
[
"Sakamoto",
"Makoto",
""
]
] | We propose a mechanism of Higgsless gauge symmetry breaking with a large mass hierarchy. We consider a 5D gauge theory on an orbifold $S^1/Z_2$. The gauge symmetry is broken by orbifolding and also nontrivial boundary conditions at fixed points. All 4D modes which survive at low energies are found to be localized around fixed points. Supersymmetry plays an important role in our mechanism. The tree-level unitarity in our model is briefly discussed. |
0711.4691 | Juraj Bohacik | Juraj Boh\'a\v{c}ik and Peter Pre\v{s}najder | Study of an Abelinization Transition in SU(2) Gluodynamics at Finite
Temperature | Conference Hadron Structure'07, September 3-7th, 2007, Modra -
Harmonia, Slovakia | Fizika B17:355-362,2008 | null | null | hep-ph | null | We discuss the problem of an effective descriptions of the phase transition
phenomena in the pure gluodynamics in SU(2) symmetric QCD. We choose the method
of calculation following the conjecture that the infrared sector of the theory
possesses the same confinement characteristic as the full theory. We show, that
analytic descriptions of this phenomena is beyond the Gaussian method of
evaluations of functional integrals. We propose a non-perturbative evaluation
of functional integral, meanwhile for two dimensional Wiener integral for
$\phi^4$ theory.
| [
{
"created": "Thu, 29 Nov 2007 11:54:01 GMT",
"version": "v1"
}
] | 2009-02-20 | [
[
"Boháčik",
"Juraj",
""
],
[
"Prešnajder",
"Peter",
""
]
] | We discuss the problem of an effective descriptions of the phase transition phenomena in the pure gluodynamics in SU(2) symmetric QCD. We choose the method of calculation following the conjecture that the infrared sector of the theory possesses the same confinement characteristic as the full theory. We show, that analytic descriptions of this phenomena is beyond the Gaussian method of evaluations of functional integrals. We propose a non-perturbative evaluation of functional integral, meanwhile for two dimensional Wiener integral for $\phi^4$ theory. |
1110.6049 | Peihong Gu | Pei-Hong Gu | A left-right symmetric model with SU(2)-triplet fermions | 4 pages. To appear in Phys. Rev. D | null | 10.1103/PhysRevD.84.097301 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider an $SU(3)_c \otimes SU(2)_L \otimes SU(2)_R \otimes U(1)_{B-L}$
left-right symmetric model with three Higgs scalars including an $SU(2)_L$
doublet, an $SU(2)_R$ doublet and an $SU(2)_L \otimes SU(2)_R$ bidoublet. In
addition to usual SU(2)-doublet fermions, our model contains SU(2)-triplet
fermions with Majorana masses. The neutral components of the left-handed
triplets can contribute a canonical seesaw while the neutral components of the
right-handed triplets associated with the right-handed neutrinos can contribute
a double/inverse-type seesaw. Our model can be embedded into an SO(10) grand
unification theory where the triplets belong to the $45=(1,3,1,0) \oplus
(1,1,3,0)\oplus ...$ representations.
| [
{
"created": "Thu, 27 Oct 2011 11:08:28 GMT",
"version": "v1"
}
] | 2015-05-30 | [
[
"Gu",
"Pei-Hong",
""
]
] | We consider an $SU(3)_c \otimes SU(2)_L \otimes SU(2)_R \otimes U(1)_{B-L}$ left-right symmetric model with three Higgs scalars including an $SU(2)_L$ doublet, an $SU(2)_R$ doublet and an $SU(2)_L \otimes SU(2)_R$ bidoublet. In addition to usual SU(2)-doublet fermions, our model contains SU(2)-triplet fermions with Majorana masses. The neutral components of the left-handed triplets can contribute a canonical seesaw while the neutral components of the right-handed triplets associated with the right-handed neutrinos can contribute a double/inverse-type seesaw. Our model can be embedded into an SO(10) grand unification theory where the triplets belong to the $45=(1,3,1,0) \oplus (1,1,3,0)\oplus ...$ representations. |
2109.06065 | Oliver Fischer Dr. | Oliver Fischer, Bruce Mellado, Stefan Antusch, Emanuele Bagnaschi,
Shankha Banerjee, Geoff Beck, Benedetta Belfatto, Matthew Bellis, Zurab
Berezhiani, Monika Blanke, Bernat Capdevila, Kingman Cheung, Andreas
Crivellin, Nishita Desai, Bhupal Dev, Rohini Godbole, Tao Han, Philip Harris,
Martin Hoferichter, Matthew Kirk, Suchita Kulkarni, Clemens Lange, Kati
Lassila-Perini, Zhen Liu, Farvah Mahmoudi, Claudio Andrea Manzari, David
Marzocca, Biswarup Mukhopadhyaya, Antonio Pich, Yifeng Ruan, Luc Schnell,
Jesse Thaler, and Susanne Westhoff | Unveiling Hidden Physics at the LHC | Whitepaper including input from the workshop "Unveiling Hidden
Physics Beyond the Standard Model at the LHC" (1-3 March 2021, online), 70
pages plus references, 17 figures, 7 tables | null | 10.1140/epjc/s10052-022-10541-4 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The field of particle physics is at the crossroads. The discovery of a
Higgs-like boson completed the Standard Model (SM), but the lacking observation
of convincing resonances Beyond the SM (BSM) offers no guidance for the future
of particle physics. On the other hand, the motivation for New Physics has not
diminished and is, in fact, reinforced by several striking anomalous results in
many experiments. Here we summarise the status of the most significant
anomalies, including the most recent results for the flavour anomalies, the
multi-lepton anomalies at the LHC, the Higgs-like excess at around 96 GeV, and
anomalies in neutrino physics, astrophysics, cosmology, and cosmic rays.
While the LHC promises up to 4/ab of integrated luminosity and far-reaching
physics programmes to unveil BSM physics, we consider the possibility that the
latter could be tested with present data, but that systemic shortcomings of the
experiments and their search strategies may preclude their discovery for
several reasons, including: final states consisting in soft particles only,
associated production processes, QCD-like final states, close-by SM resonances,
and SUSY scenarios where no missing energy is produced.
New search strategies could help to unveil the hidden BSM signatures, devised
by making use of the CERN open data as a new testing ground. We discuss the
CERN open data with its policies, challenges, and potential usefulness for the
community. We showcase the example of the CMS collaboration, which is the only
collaboration regularly releasing some of its data. We find it important to
stress that individuals using public data for their own research does not imply
competition with experimental efforts, but rather provides unique opportunities
to give guidance for further BSM searches by the collaborations. Wide access to
open data is paramount to fully exploit the LHCs potential.
| [
{
"created": "Mon, 13 Sep 2021 15:34:00 GMT",
"version": "v1"
}
] | 2022-08-24 | [
[
"Fischer",
"Oliver",
""
],
[
"Mellado",
"Bruce",
""
],
[
"Antusch",
"Stefan",
""
],
[
"Bagnaschi",
"Emanuele",
""
],
[
"Banerjee",
"Shankha",
""
],
[
"Beck",
"Geoff",
""
],
[
"Belfatto",
"Benedetta",
""
],
[
"Bellis",
"Matthew",
""
],
[
"Berezhiani",
"Zurab",
""
],
[
"Blanke",
"Monika",
""
],
[
"Capdevila",
"Bernat",
""
],
[
"Cheung",
"Kingman",
""
],
[
"Crivellin",
"Andreas",
""
],
[
"Desai",
"Nishita",
""
],
[
"Dev",
"Bhupal",
""
],
[
"Godbole",
"Rohini",
""
],
[
"Han",
"Tao",
""
],
[
"Harris",
"Philip",
""
],
[
"Hoferichter",
"Martin",
""
],
[
"Kirk",
"Matthew",
""
],
[
"Kulkarni",
"Suchita",
""
],
[
"Lange",
"Clemens",
""
],
[
"Lassila-Perini",
"Kati",
""
],
[
"Liu",
"Zhen",
""
],
[
"Mahmoudi",
"Farvah",
""
],
[
"Manzari",
"Claudio Andrea",
""
],
[
"Marzocca",
"David",
""
],
[
"Mukhopadhyaya",
"Biswarup",
""
],
[
"Pich",
"Antonio",
""
],
[
"Ruan",
"Yifeng",
""
],
[
"Schnell",
"Luc",
""
],
[
"Thaler",
"Jesse",
""
],
[
"Westhoff",
"Susanne",
""
]
] | The field of particle physics is at the crossroads. The discovery of a Higgs-like boson completed the Standard Model (SM), but the lacking observation of convincing resonances Beyond the SM (BSM) offers no guidance for the future of particle physics. On the other hand, the motivation for New Physics has not diminished and is, in fact, reinforced by several striking anomalous results in many experiments. Here we summarise the status of the most significant anomalies, including the most recent results for the flavour anomalies, the multi-lepton anomalies at the LHC, the Higgs-like excess at around 96 GeV, and anomalies in neutrino physics, astrophysics, cosmology, and cosmic rays. While the LHC promises up to 4/ab of integrated luminosity and far-reaching physics programmes to unveil BSM physics, we consider the possibility that the latter could be tested with present data, but that systemic shortcomings of the experiments and their search strategies may preclude their discovery for several reasons, including: final states consisting in soft particles only, associated production processes, QCD-like final states, close-by SM resonances, and SUSY scenarios where no missing energy is produced. New search strategies could help to unveil the hidden BSM signatures, devised by making use of the CERN open data as a new testing ground. We discuss the CERN open data with its policies, challenges, and potential usefulness for the community. We showcase the example of the CMS collaboration, which is the only collaboration regularly releasing some of its data. We find it important to stress that individuals using public data for their own research does not imply competition with experimental efforts, but rather provides unique opportunities to give guidance for further BSM searches by the collaborations. Wide access to open data is paramount to fully exploit the LHCs potential. |
hep-ph/0205180 | Yasutaka Takanishi | H. B. Nielsen and Y. Takanishi | Five Adjustable Parameter Fit of Quark and Lepton Masses and Mixings | 16 pages, no figure, latex2e;v2 text slightly modified, refs. added | Phys.Lett. B543 (2002) 249-260 | 10.1016/S0370-2693(02)02439-5 | DESY 02-066, NBI-HE-02-07 | hep-ph | null | We develop a model of ours fitting the quark and lepton masses and mixing
angles by removing from the model a Higgs field previously introduced to
organise a large atmospheric mixing angle for neutrino oscillations. Due to the
off-diagonal elements dominating in the see-saw neutrino mass matrix the large
atmospheric mixing angle comes essentially by itself. It turns out that we have
now only five adjustable Higgs field vacuum expectation values needed to fit
all the masses and mixings order of magnitudewise taking into account the
renormalisation group runnings in all sectors. The CHOOZ angle comes out close
to the experimental bound.
| [
{
"created": "Thu, 16 May 2002 14:09:39 GMT",
"version": "v1"
},
{
"created": "Mon, 24 Jun 2002 18:39:43 GMT",
"version": "v2"
}
] | 2010-04-05 | [
[
"Nielsen",
"H. B.",
""
],
[
"Takanishi",
"Y.",
""
]
] | We develop a model of ours fitting the quark and lepton masses and mixing angles by removing from the model a Higgs field previously introduced to organise a large atmospheric mixing angle for neutrino oscillations. Due to the off-diagonal elements dominating in the see-saw neutrino mass matrix the large atmospheric mixing angle comes essentially by itself. It turns out that we have now only five adjustable Higgs field vacuum expectation values needed to fit all the masses and mixings order of magnitudewise taking into account the renormalisation group runnings in all sectors. The CHOOZ angle comes out close to the experimental bound. |
1210.2263 | Zhi-Qiang Guo | Zhi-Qiang Guo and Ivan Schmidt | Gauge Invariant Descriptions of Gluon Polarizations | 10 pages,no figures. V2: improved presentations, references added | null | 10.1103/PhysRevD.87.114016 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose methods to construct gauge invariant decompositions of the nucleon
spin, particularly gauge invariant descriptions of the gluon polarization. We
show that gauge invariant decompositions of the nucleon spin can be derived
naturally from the conserved current of a generalized Lorentz transformation by
the Noether theorem. We propose a gauge invariant extension of the Chern-Simons
current as a possible description of the gluon spin, and we also examine the
problem of gauge dependence of this extended Chern-Simons current.
| [
{
"created": "Mon, 8 Oct 2012 12:50:20 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Apr 2013 18:49:49 GMT",
"version": "v2"
}
] | 2013-06-26 | [
[
"Guo",
"Zhi-Qiang",
""
],
[
"Schmidt",
"Ivan",
""
]
] | We propose methods to construct gauge invariant decompositions of the nucleon spin, particularly gauge invariant descriptions of the gluon polarization. We show that gauge invariant decompositions of the nucleon spin can be derived naturally from the conserved current of a generalized Lorentz transformation by the Noether theorem. We propose a gauge invariant extension of the Chern-Simons current as a possible description of the gluon spin, and we also examine the problem of gauge dependence of this extended Chern-Simons current. |
0711.3450 | Passemar Emilie | Veronique Bernard, Emilie Passemar | Matching Chiral Perturbation Theory and the Dispersive Representation of
the Scalar Kpi Form Factor | 13 pages, 1 figure, typos corrected, discussion slightly extended,
accepted for publication in Phys. Lett. B | Phys.Lett.B661:95-102,2008 | 10.1016/j.physletb.2008.02.004 | null | hep-ph hep-ex hep-lat nucl-ex nucl-th | null | We perform a matching of the two loop-chiral perturbation theory
representation of the scalar Kpi form factor to a dispersive one. Knowing the
value of F_K/F_pi and f_+(0) in the Standard Model (SM) allows to determine two
O(p^6) LECs, the slope of the scalar form factor and the deviation of the
Callan-Treiman theorem. Going beyond the SM and assuming the knowledge of the
slope of the scalar form factor from experiment, the matching allows us to
determine the ratio of F_K/F_pi, f_+(0), a certain combination of non-standard
couplings, the deviation of the Callan-Treiman theorem and the two O(p^6) LECs.
| [
{
"created": "Wed, 21 Nov 2007 20:54:45 GMT",
"version": "v1"
},
{
"created": "Thu, 13 Mar 2008 10:24:19 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Bernard",
"Veronique",
""
],
[
"Passemar",
"Emilie",
""
]
] | We perform a matching of the two loop-chiral perturbation theory representation of the scalar Kpi form factor to a dispersive one. Knowing the value of F_K/F_pi and f_+(0) in the Standard Model (SM) allows to determine two O(p^6) LECs, the slope of the scalar form factor and the deviation of the Callan-Treiman theorem. Going beyond the SM and assuming the knowledge of the slope of the scalar form factor from experiment, the matching allows us to determine the ratio of F_K/F_pi, f_+(0), a certain combination of non-standard couplings, the deviation of the Callan-Treiman theorem and the two O(p^6) LECs. |
2211.15101 | Masaki J.S. Yang | Masaki J. S. Yang | Chiral perturbative analysis for an almost massless neutrino in the
type-I seesaw mechanism | 12 pages, final version will be published in Nuclear Physics B | null | 10.1016/j.nuclphysb.2023.116318 | STUPP-22-260 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we perform chiral perturbative analysis of an approximate
lepton number symmetry associated with a sufficiently light neutrino in the
type-I seesaw mechanism. For the Dirac mass matrix $m_{D} = (\bm A \, , \bm B
\, , \bm C)$, linearly independent components of $\bm C$ from $\bm A$ and $\bm
B$ are treated as symmetry-breaking parameters. A deviation in the eigenvector
of the massless mode $\delta \bm u$ occurs in the first-order perturbation and
the lightest mass $m_{1 \, \rm or \, 3} \propto \det m_{D}^{2} / M_{3}$ emerges
in the second-order. By solving the perturbation theory, we obtained specific
expressions of $\delta \bm u$ and $m_{1 \, \rm or \, 3}$. As a result, two
complex parameters in $m_{D}$ are bounded to some extent from the eigenvector.
These constraints are associated with the chiral symmetry and are not
susceptible to renormalization.
| [
{
"created": "Mon, 28 Nov 2022 07:35:34 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Mar 2023 00:10:15 GMT",
"version": "v2"
},
{
"created": "Mon, 14 Aug 2023 04:39:02 GMT",
"version": "v3"
}
] | 2023-08-24 | [
[
"Yang",
"Masaki J. S.",
""
]
] | In this paper, we perform chiral perturbative analysis of an approximate lepton number symmetry associated with a sufficiently light neutrino in the type-I seesaw mechanism. For the Dirac mass matrix $m_{D} = (\bm A \, , \bm B \, , \bm C)$, linearly independent components of $\bm C$ from $\bm A$ and $\bm B$ are treated as symmetry-breaking parameters. A deviation in the eigenvector of the massless mode $\delta \bm u$ occurs in the first-order perturbation and the lightest mass $m_{1 \, \rm or \, 3} \propto \det m_{D}^{2} / M_{3}$ emerges in the second-order. By solving the perturbation theory, we obtained specific expressions of $\delta \bm u$ and $m_{1 \, \rm or \, 3}$. As a result, two complex parameters in $m_{D}$ are bounded to some extent from the eigenvector. These constraints are associated with the chiral symmetry and are not susceptible to renormalization. |
1903.11034 | Maurice Benayoun | M. Benayoun, L. DelBuono, F. Jegerlehner | BHLS$_2$, a New Breaking of the HLS Model and its Phenomenology | Final version corrected and extended. Version accepted for
publication in EPJC | null | 10.1140/epjc/s10052-020-7611-9 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Previous studies have shown that the Hidden Local Symmetry (HLS) Model,
supplied with appropriate symmetry breaking, provides an Effective Lagrangian
(BHLS) able to encompass a large number of processes within a unified
framework. A global fit provides a simultaneous description of the $e^+ e^-$
annihilation into $\pi^+\pi^-$, $\pi^0\gamma$, $\eta \gamma$,
$\pi^+\pi^-\pi^0$, $K^+K^-$, $K_L K_S$, the dipion spectrum in the $\tau$ decay
and other light meson partial widths. Additional breaking schemes extend its
scope to spacelike processes within a new framework (BHLS$_2$). The
phenomenology previously explored with BHLS is revisited in the BHLS$_2$
context with emphasis on the $\Phi$ mass region. It is shown that BHLS$_2$
addresses the close spacelike region covered by NA7 and Fermilab data; also,the
Lattice QCD pion form factor is accurately predicted by BHLS$_2$ using fits to
annihilation data only. These channels contribution to $a_\mu$ over the range
of validity of BHLS$_2$ is shown to strongly reduce the former BHLS
systematics. The uncertainty on $a_\mu^{\rm th}(\sqrt{s}< 1.05$ GeV) is much
improved compared to standard approaches relying on direct integration methods
of measured spectra. Using the BHLS$_2$ results, the leading order HVP
contribution to the muon anomalous moment is $a_\mu^{HVP-LO}= 686.65 \pm 3.01
+(+1.16,-0.75)_{syst.}$ in units of $10^{-10}$. Using a conservative estimate
for the light--by--light contribution, our evaluation is $a_\mu^{\rm th}=\left
[11\,659\,175.96 \pm 4.17 +(+1.16,-0.75)_{syst.}\right]\times 10^{-10}$. The
$\rho^0\gamma$ mixing in dispersive and LQCD approaches is discussed and may
amount to a shift $\delta a_\mu[\pi\pi]_{\rho\gamma} = +(3.10\pm0.31)\times
10^{-10}$ at LO+NLO, presently treated as additional systematics. Taking this
shift into account, $a_\mu^{\rm th}-a_\mu^{\rm BNL}$ exhibits a significance
not smaller than $3.8 \sigma$.
| [
{
"created": "Tue, 26 Mar 2019 17:31:45 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Apr 2019 11:35:22 GMT",
"version": "v2"
},
{
"created": "Wed, 8 Jan 2020 15:04:16 GMT",
"version": "v3"
}
] | 2020-02-19 | [
[
"Benayoun",
"M.",
""
],
[
"DelBuono",
"L.",
""
],
[
"Jegerlehner",
"F.",
""
]
] | Previous studies have shown that the Hidden Local Symmetry (HLS) Model, supplied with appropriate symmetry breaking, provides an Effective Lagrangian (BHLS) able to encompass a large number of processes within a unified framework. A global fit provides a simultaneous description of the $e^+ e^-$ annihilation into $\pi^+\pi^-$, $\pi^0\gamma$, $\eta \gamma$, $\pi^+\pi^-\pi^0$, $K^+K^-$, $K_L K_S$, the dipion spectrum in the $\tau$ decay and other light meson partial widths. Additional breaking schemes extend its scope to spacelike processes within a new framework (BHLS$_2$). The phenomenology previously explored with BHLS is revisited in the BHLS$_2$ context with emphasis on the $\Phi$ mass region. It is shown that BHLS$_2$ addresses the close spacelike region covered by NA7 and Fermilab data; also,the Lattice QCD pion form factor is accurately predicted by BHLS$_2$ using fits to annihilation data only. These channels contribution to $a_\mu$ over the range of validity of BHLS$_2$ is shown to strongly reduce the former BHLS systematics. The uncertainty on $a_\mu^{\rm th}(\sqrt{s}< 1.05$ GeV) is much improved compared to standard approaches relying on direct integration methods of measured spectra. Using the BHLS$_2$ results, the leading order HVP contribution to the muon anomalous moment is $a_\mu^{HVP-LO}= 686.65 \pm 3.01 +(+1.16,-0.75)_{syst.}$ in units of $10^{-10}$. Using a conservative estimate for the light--by--light contribution, our evaluation is $a_\mu^{\rm th}=\left [11\,659\,175.96 \pm 4.17 +(+1.16,-0.75)_{syst.}\right]\times 10^{-10}$. The $\rho^0\gamma$ mixing in dispersive and LQCD approaches is discussed and may amount to a shift $\delta a_\mu[\pi\pi]_{\rho\gamma} = +(3.10\pm0.31)\times 10^{-10}$ at LO+NLO, presently treated as additional systematics. Taking this shift into account, $a_\mu^{\rm th}-a_\mu^{\rm BNL}$ exhibits a significance not smaller than $3.8 \sigma$. |
1011.6167 | Stephen King | Stephen F. King | Vacuum misalignment corrections to tri-bimaximal mixing and form
dominance | Published version, 29 pages | JHEP 1101:115,2011 | 10.1007/JHEP01(2011)115 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Tri-bimaximal neutrino mixing may arise from see-saw models based on family
symmetry which is spontaneously broken by flavons with particular vacuum
alignments. However recent analyses hint that tri-bimaximal mixing may be
insensitive to the precise form of vacuum alignment. In this paper we derive
approximate analytic results which express the deviations from tri-bimaximal
neutrino mixing due to vacuum misalignment. We also relate vacuum misalignment
to departures from form dominance, corresponding to deviations from the real
orthogonal $R$ matrix, where such corrections are necessary to allow for
successful leptogenesis. The analytic results show that the corrections to
tri-bimaximal mixing and form dominance depend on the pattern of the vacuum
misalignment, with the two effects being uncorrelated.
| [
{
"created": "Mon, 29 Nov 2010 09:48:26 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Mar 2011 07:02:12 GMT",
"version": "v2"
}
] | 2011-03-04 | [
[
"King",
"Stephen F.",
""
]
] | Tri-bimaximal neutrino mixing may arise from see-saw models based on family symmetry which is spontaneously broken by flavons with particular vacuum alignments. However recent analyses hint that tri-bimaximal mixing may be insensitive to the precise form of vacuum alignment. In this paper we derive approximate analytic results which express the deviations from tri-bimaximal neutrino mixing due to vacuum misalignment. We also relate vacuum misalignment to departures from form dominance, corresponding to deviations from the real orthogonal $R$ matrix, where such corrections are necessary to allow for successful leptogenesis. The analytic results show that the corrections to tri-bimaximal mixing and form dominance depend on the pattern of the vacuum misalignment, with the two effects being uncorrelated. |
hep-ph/9408269 | null | Michael E. Peskin | Complementarity of $e^+e^-$ and $pp$ Colliders for the Exploration of
Electroweak Symmetry Breaking | phyzzx macropackage, 30 pp | null | null | SLAC-PUB-6582 | hep-ph | null | I review the physics capabilities of the machines proposed for the next
generation of high-energy experimentation: in hadron physics, the LHC, and in
electron physics, a $500$--$1500$ GeV $e^+e^-$ linear collider. Using for
illustration two specific models of electroweak symmetry breaking, I show how
the $pp$ and $e^+e^-$ techniques are expected to complement one another in the
exploration of the next scale of physics. [invited lecture at the 22nd INS
Symposium, Tokyo] (text only; complete paper with figures and tables available
by anonymous ftp from preprint.slac.stanford.edu, in the directory
pub/preprints/hep-ph/9408)
| [
{
"created": "Thu, 11 Aug 1994 02:00:00 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Peskin",
"Michael E.",
""
]
] | I review the physics capabilities of the machines proposed for the next generation of high-energy experimentation: in hadron physics, the LHC, and in electron physics, a $500$--$1500$ GeV $e^+e^-$ linear collider. Using for illustration two specific models of electroweak symmetry breaking, I show how the $pp$ and $e^+e^-$ techniques are expected to complement one another in the exploration of the next scale of physics. [invited lecture at the 22nd INS Symposium, Tokyo] (text only; complete paper with figures and tables available by anonymous ftp from preprint.slac.stanford.edu, in the directory pub/preprints/hep-ph/9408) |
hep-ph/9802413 | Jiri Hosek | J.Hosek | Vacuum engineering with DCC | 8 pages, revtex | null | null | null | hep-ph | null | Formation of a vacuum like domain of the strong-interaction chiral condensate
misaligned with respect to the electroweak symmetry breaking arguably modifies
the mass spectrum of electroweak gauge bosons and their interactions in that
domain in an observable manner. In particular,photon acquires the mass
$m_{\gamma}\sim{1/2}f_{\pi}\sin2\theta_{W}$.
| [
{
"created": "Wed, 25 Feb 1998 08:00:06 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Hosek",
"J.",
""
]
] | Formation of a vacuum like domain of the strong-interaction chiral condensate misaligned with respect to the electroweak symmetry breaking arguably modifies the mass spectrum of electroweak gauge bosons and their interactions in that domain in an observable manner. In particular,photon acquires the mass $m_{\gamma}\sim{1/2}f_{\pi}\sin2\theta_{W}$. |
1208.5685 | Cristiano Brenner Mariotto | C. Brenner Mariotto and M.V.T. Machado | An analysis on the photoproduction of massive gauge bosons at the LHeC | 6 pages, 3 figures, 2 tables | Phys. Rev. D 86, 033009 (2012) | 10.1103/PhysRevD.86.033009 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work we investigate the photoproduction of massive gauge bosons,
$W^{\pm}$ and $Z^0$, as part of relevant physics topics to be studied in the
proposed electron-proton collider, the LHeC. The estimates for production cross
sections and the number of events are presented. In addition, motivated by the
intensive studies to test the deviations from the Standard Model at present and
future colliders, we discuss the $W^{\pm}$ asymmetries and perform an analysis
on the role played by anomalous $WW\gamma$ coupling.
| [
{
"created": "Tue, 28 Aug 2012 15:13:48 GMT",
"version": "v1"
}
] | 2012-08-29 | [
[
"Mariotto",
"C. Brenner",
""
],
[
"Machado",
"M. V. T.",
""
]
] | In this work we investigate the photoproduction of massive gauge bosons, $W^{\pm}$ and $Z^0$, as part of relevant physics topics to be studied in the proposed electron-proton collider, the LHeC. The estimates for production cross sections and the number of events are presented. In addition, motivated by the intensive studies to test the deviations from the Standard Model at present and future colliders, we discuss the $W^{\pm}$ asymmetries and perform an analysis on the role played by anomalous $WW\gamma$ coupling. |
1811.08720 | Rafael L. Delgado | Rafael L. Delgado, A.Dobado, D.Espriu, C.Garcia-Garcia, M.J.Herrero,
X.Marcano and J.J.Sanz-Cillero | Collider phenomenology of vector resonances in WZ scattering processes | 8 pages, 5 figures, contributed to the XIII Quark Confinement and the
Hadron Spectrum - Confinement2018, 31 July - 6 August 2018, Maynooth
University, Ireland | null | null | TUM-EFT 114/18, VBSCAN-PUB-07-18 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the production of vector resonances at the LHC via $WZ$ scattering
processes and explore the sensitivities to these resonances for the expected
future LHC luminosities. The electroweak chiral Lagrangian and the Inverse
Amplitude Method (IAM) are used for analyzing a dynamically generated vector
resonance, whose origin would be the (hypothetically strong) self interactions
of the longitudinal gauge bosons, $W_L$ and $Z_L$. We implement the unitarized
scattering amplitudes into a single model, the IAM-MC, that has been adapted to
MadGraph~5. It is written in terms of the electroweak chiral Lagrangian and an
additional effective Proca Lagrangian for the vector resonances, so that it
reproduces the resonant behavior of the IAM and allows us to perform a
realistic study of signal versus background at the LHC. We focus on the $pp\to
WZjj$ channel, discussing first on the potential of the hadronic and
semileptonic channels of the final $WZ$, and next exploring in more detail the
clearest signals. These are provided by the leptonic decays of the gauge
bosons, leading to a final state with $l^+_1l^-_1l^+_2\nu jj$, $l=e,\mu$,
having a very distinctive signature, and showing clearly the emergence of the
resonances with masses in the range of $1.5$-$2.5\,{\rm TeV}$, which we have
explored.
| [
{
"created": "Wed, 21 Nov 2018 13:33:27 GMT",
"version": "v1"
}
] | 2019-02-04 | [
[
"Delgado",
"Rafael L.",
""
],
[
"Dobado",
"A.",
""
],
[
"Espriu",
"D.",
""
],
[
"Garcia-Garcia",
"C.",
""
],
[
"Herrero",
"M. J.",
""
],
[
"Marcano",
"X.",
""
],
[
"Sanz-Cillero",
"J. J.",
""
]
] | We study the production of vector resonances at the LHC via $WZ$ scattering processes and explore the sensitivities to these resonances for the expected future LHC luminosities. The electroweak chiral Lagrangian and the Inverse Amplitude Method (IAM) are used for analyzing a dynamically generated vector resonance, whose origin would be the (hypothetically strong) self interactions of the longitudinal gauge bosons, $W_L$ and $Z_L$. We implement the unitarized scattering amplitudes into a single model, the IAM-MC, that has been adapted to MadGraph~5. It is written in terms of the electroweak chiral Lagrangian and an additional effective Proca Lagrangian for the vector resonances, so that it reproduces the resonant behavior of the IAM and allows us to perform a realistic study of signal versus background at the LHC. We focus on the $pp\to WZjj$ channel, discussing first on the potential of the hadronic and semileptonic channels of the final $WZ$, and next exploring in more detail the clearest signals. These are provided by the leptonic decays of the gauge bosons, leading to a final state with $l^+_1l^-_1l^+_2\nu jj$, $l=e,\mu$, having a very distinctive signature, and showing clearly the emergence of the resonances with masses in the range of $1.5$-$2.5\,{\rm TeV}$, which we have explored. |
1410.0554 | Andrei Kataev | A.L.Kataev (Moscow, INR) and S.V. Mikhailov (Dubna, JINR) | $\{\beta\}$-expansion in QCD, its conformal symmetry limit: theory +
applications | 6 pages, Based on the talk given at the 17th International Conderence
on Quantum Chromodynamics (QCD 14) (29 june- 3 july 2014, Montpellier,
France), to appear in Nuclear and Particle Physics Proceedings ; misprints
corrected, 1 reference to the journal publication specified; physical results
and theoretical conclusions unchanged | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The basis of the $\{\beta\}$-expansion for the perturbative series evaluated
in the $\overline{MS}$ scheme for the renormalization group invariant
quantities is summarized.Comparison with a similar representation,used within
the BLM-motivated Principle of Maximal Conformality,is discussed.We stress that
the original $\{\beta\}$-expansion contains a completed list of terms rather
than its PMC analog. The arguments in favour of the complete
$\{\beta\}$-expansion are presented. They are based on the relations which
follow from the power $\beta$-function generalization of the Crewther relation
for the nonsinglet $\overline{MS}$ contributions to the Adler
$D^{NS}$-functionand to the Bjorken sum rule $C^{Bjp}_{NS}$ of the polarized
lepton-nucleon scattering. The terms of the complete $\{\beta\}$-expansionat
the $O(\alpha_s^3)$ level for $D^{NS}$ and $C^{Bjp}_{NS}$ are presented. These
perturbative results are expressed in the PMC-type form. The problem of
applications of these expressions for phenomenological applications is
summarized.
| [
{
"created": "Thu, 2 Oct 2014 13:56:47 GMT",
"version": "v1"
},
{
"created": "Sat, 17 Jan 2015 11:05:08 GMT",
"version": "v2"
}
] | 2015-01-20 | [
[
"Kataev",
"A. L.",
"",
"Moscow, INR"
],
[
"Mikhailov",
"S. V.",
"",
"Dubna, JINR"
]
] | The basis of the $\{\beta\}$-expansion for the perturbative series evaluated in the $\overline{MS}$ scheme for the renormalization group invariant quantities is summarized.Comparison with a similar representation,used within the BLM-motivated Principle of Maximal Conformality,is discussed.We stress that the original $\{\beta\}$-expansion contains a completed list of terms rather than its PMC analog. The arguments in favour of the complete $\{\beta\}$-expansion are presented. They are based on the relations which follow from the power $\beta$-function generalization of the Crewther relation for the nonsinglet $\overline{MS}$ contributions to the Adler $D^{NS}$-functionand to the Bjorken sum rule $C^{Bjp}_{NS}$ of the polarized lepton-nucleon scattering. The terms of the complete $\{\beta\}$-expansionat the $O(\alpha_s^3)$ level for $D^{NS}$ and $C^{Bjp}_{NS}$ are presented. These perturbative results are expressed in the PMC-type form. The problem of applications of these expressions for phenomenological applications is summarized. |
1104.2601 | Ivo de Medeiros Varzielas | Ivo de Medeiros Varzielas | Family symmetries and alignment in multi-Higgs doublet models | 4 pages | Phys.Lett.B701:597-600,2011 | 10.1016/j.physletb.2011.06.042 | DO-TH 11/09 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The exact alignment of the Yukawa structures on multi-Higgs doublet models
provides cancellation of tree-level flavour changing couplings of neutral
scalar fields. We show that family symmetries can provide a suitable
justification for the Yukawa alignment.
| [
{
"created": "Wed, 13 Apr 2011 20:00:15 GMT",
"version": "v1"
}
] | 2011-07-20 | [
[
"Varzielas",
"Ivo de Medeiros",
""
]
] | The exact alignment of the Yukawa structures on multi-Higgs doublet models provides cancellation of tree-level flavour changing couplings of neutral scalar fields. We show that family symmetries can provide a suitable justification for the Yukawa alignment. |
hep-ph/9803496 | Anders Edin | A. Edin, G. Ingelman | A model for the parton distributions in hadrons | 12 pages, Latex, 5 figures. Added discussion on the applicability of
the model at small Q^2. Figure 3 modified to show smaller Q^2 | Phys.Lett.B432:402-410,1998 | 10.1016/S0370-2693(98)00659-5 | TSL/ISV-98-0193, DESY 98-035 | hep-ph | null | A simple model is presented for the parton distributions in hadrons. The
parton momenta in the hadron rest frame are derived from a spherically
symmetric, Gaussian, distribution having a width motivated by the Heisenberg
uncertainty relation applied to the hadron size. Valence quarks and gluons
originate from the `bare' hadron, while sea partons arise mainly from pions in
hadronic fluctuations. Starting from a low Q^2 scale, the distributions are
evolved with next-to-leading order DGLAP and give the proton structure function
F2(x,Q^2) in good agreement with deep inelastic scattering data.
| [
{
"created": "Tue, 31 Mar 1998 14:14:45 GMT",
"version": "v1"
},
{
"created": "Mon, 11 May 1998 12:33:38 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Edin",
"A.",
""
],
[
"Ingelman",
"G.",
""
]
] | A simple model is presented for the parton distributions in hadrons. The parton momenta in the hadron rest frame are derived from a spherically symmetric, Gaussian, distribution having a width motivated by the Heisenberg uncertainty relation applied to the hadron size. Valence quarks and gluons originate from the `bare' hadron, while sea partons arise mainly from pions in hadronic fluctuations. Starting from a low Q^2 scale, the distributions are evolved with next-to-leading order DGLAP and give the proton structure function F2(x,Q^2) in good agreement with deep inelastic scattering data. |
2003.05702 | Rafal Maciula | Rafal Maciula | QCD predictions for open charm meson production at the LHCb in
fixed-target experiment | 24 pages, 8 figures. arXiv admin note: text overlap with
arXiv:1905.06697 | Phys. Rev. D 102, 014028 (2020) | 10.1103/PhysRevD.102.014028 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate open charm meson production in fixed-target LHCb experiment at
$\sqrt{s}=86.6$ GeV in $p+^4\!\mathrm{He}$ collisions. Theoretical calculations
of charm cross section are done in the framework of the $k_{T}$-factorization
approach. Its application in the kinematical range never examined before is
carefully discussed. We consider different schemes for the calculations
relevant for different unintegrated (transverse momentum dependent) parton
densities in a proton. We include in the analysis both CCFM- and DGLAP-based
models of unintegrated parton distributions appropriate for the considered
kinematics. Integrated as well as differential cross sections as a function of
$D^{0}$ meson rapidity and transverse momentum are shown and compared with the
experimental data. As a reference point, predictions of next-to-leading order
collinear approach are also presented and discussed. A very good agreement
between the experimental data and the $k_{T}$-factorization predictions was
obtained. Both the CCFM and the DGLAP-based frameworks for parton distributions
in a proton are successfully used to explain the LHCb fixed-target open charm
cross section.
| [
{
"created": "Thu, 12 Mar 2020 10:53:39 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Mar 2020 20:08:16 GMT",
"version": "v2"
}
] | 2020-07-22 | [
[
"Maciula",
"Rafal",
""
]
] | We investigate open charm meson production in fixed-target LHCb experiment at $\sqrt{s}=86.6$ GeV in $p+^4\!\mathrm{He}$ collisions. Theoretical calculations of charm cross section are done in the framework of the $k_{T}$-factorization approach. Its application in the kinematical range never examined before is carefully discussed. We consider different schemes for the calculations relevant for different unintegrated (transverse momentum dependent) parton densities in a proton. We include in the analysis both CCFM- and DGLAP-based models of unintegrated parton distributions appropriate for the considered kinematics. Integrated as well as differential cross sections as a function of $D^{0}$ meson rapidity and transverse momentum are shown and compared with the experimental data. As a reference point, predictions of next-to-leading order collinear approach are also presented and discussed. A very good agreement between the experimental data and the $k_{T}$-factorization predictions was obtained. Both the CCFM and the DGLAP-based frameworks for parton distributions in a proton are successfully used to explain the LHCb fixed-target open charm cross section. |
1103.4350 | Mads Toudal Frandsen | Mads T. Frandsen, Subir Sarkar and Kai Schmidt-Hoberg (Oxford) | Light asymmetric dark matter from new strong dynamics | 4 pages, 4 figs. (RevTex) | Phys.Rev.D84:051703,2011 | 10.1103/PhysRevD.84.051703 | OUTP-11-35-P | hep-ph astro-ph.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A ~5 GeV `dark baryon' with a cosmic asymmetry similar to that of baryons is
a natural candidate for the dark matter. We study the possibility of generating
such a state through dynamical electroweak symmetry breaking, and show that it
can share the relic baryon asymmetry via sphaleron interactions, even though it
has no electroweak interactions. The scattering cross-section on nucleons,
estimated in analogy to QCD, is within reach of underground direct detection
experiments.
| [
{
"created": "Tue, 22 Mar 2011 19:14:05 GMT",
"version": "v1"
}
] | 2011-09-28 | [
[
"Frandsen",
"Mads T.",
"",
"Oxford"
],
[
"Sarkar",
"Subir",
"",
"Oxford"
],
[
"Schmidt-Hoberg",
"Kai",
"",
"Oxford"
]
] | A ~5 GeV `dark baryon' with a cosmic asymmetry similar to that of baryons is a natural candidate for the dark matter. We study the possibility of generating such a state through dynamical electroweak symmetry breaking, and show that it can share the relic baryon asymmetry via sphaleron interactions, even though it has no electroweak interactions. The scattering cross-section on nucleons, estimated in analogy to QCD, is within reach of underground direct detection experiments. |
hep-ph/0102158 | Michael McNeil Forbes | Michael McNeil Forbes, Ariel R. Zhitnitsky (University of British
Columbia, Canada) | Primordial Galactic Magnetic Fields: An Application of QCD Domain Walls | 17 pages, 1 figure. (REVTeX 4) | null | null | null | hep-ph astro-ph nucl-th | null | We present a mechanism for generating primordial magnetic fields with large
correlation lengths on the order of 100 kpc today. The mechanism is based on
recently conjectured QCD domain walls or similar CP violating domain walls with
QCD scale structure. Such domain walls align the electric and magnetic dipole
moments of the nucleons shortly after the QCD phase transition, producing
electromagnetic fields correlated along the domain walls. Through the Kibble
mechanism, the domain walls attain Hubble-scale correlations which they
transfer to the aligned electromagnetic fields. Due to the CP violation, the
Hubble-scale walls produce helical (non-zero Chern-Simons) magnetohydrodynamic
turbulence which then undergoes an inverse cascade, allowing the correlation
lengths to grow to 100 kpc today. We present an estimate the magnitude of the
generated electromagnetic fields in terms of the QCD parameters. We also
discuss some other unexplained astrophysical phenomena which may be related to
this mechanism. In particular, we discuss the relation between primordial
magnetic fields and the Greisen-Zatsepin-Kuzmin (GZK) cutoff violations. We
also outline how, by creating inhomogeneities in the nucleon density, QCD
domain walls may lead to inhomogeneous big bang nucleosynthesis (IBBN)
explaining the Omega_B excess recently measured through cosmic microwave
background (CMB) distortions.
| [
{
"created": "Tue, 13 Feb 2001 23:52:57 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Forbes",
"Michael McNeil",
"",
"University of British\n Columbia, Canada"
],
[
"Zhitnitsky",
"Ariel R.",
"",
"University of British\n Columbia, Canada"
]
] | We present a mechanism for generating primordial magnetic fields with large correlation lengths on the order of 100 kpc today. The mechanism is based on recently conjectured QCD domain walls or similar CP violating domain walls with QCD scale structure. Such domain walls align the electric and magnetic dipole moments of the nucleons shortly after the QCD phase transition, producing electromagnetic fields correlated along the domain walls. Through the Kibble mechanism, the domain walls attain Hubble-scale correlations which they transfer to the aligned electromagnetic fields. Due to the CP violation, the Hubble-scale walls produce helical (non-zero Chern-Simons) magnetohydrodynamic turbulence which then undergoes an inverse cascade, allowing the correlation lengths to grow to 100 kpc today. We present an estimate the magnitude of the generated electromagnetic fields in terms of the QCD parameters. We also discuss some other unexplained astrophysical phenomena which may be related to this mechanism. In particular, we discuss the relation between primordial magnetic fields and the Greisen-Zatsepin-Kuzmin (GZK) cutoff violations. We also outline how, by creating inhomogeneities in the nucleon density, QCD domain walls may lead to inhomogeneous big bang nucleosynthesis (IBBN) explaining the Omega_B excess recently measured through cosmic microwave background (CMB) distortions. |
2005.04760 | Ilia Belov | A. V. Berezhnoy, I. N. Belov and A. K. Likhoded | The production of excited states of doubly heavy baryons at the Large
Hadron Collider | null | null | 10.1134/S1063778820060058 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the framework of diquark model for production we discuss the yields and
observation prospects for excited states of doubly heavy baryons at LHC
kinematic conditions.
| [
{
"created": "Sun, 10 May 2020 19:35:22 GMT",
"version": "v1"
}
] | 2021-03-17 | [
[
"Berezhnoy",
"A. V.",
""
],
[
"Belov",
"I. N.",
""
],
[
"Likhoded",
"A. K.",
""
]
] | In the framework of diquark model for production we discuss the yields and observation prospects for excited states of doubly heavy baryons at LHC kinematic conditions. |
hep-ph/0412122 | Chris Quigg | Gabriela Barenboim, Olga Mena Requejo, Chris Quigg | Diagnostic Potential of Cosmic-Neutrino Absorption Spectroscopy | 25 pages, 26 figures (in 46 files), uses RevTeX | Phys.Rev.D71:083002,2005 | 10.1103/PhysRevD.71.083002 | FERMILAB-Pub-04/379-T | hep-ph astro-ph | null | Annihilation of extremely energetic cosmic neutrinos on the relic-neutrino
background can give rise to absorption lines at energies corresponding to
formation of the electroweak gauge boson $Z^{0}$. The positions of the
absorption dips are set by the masses of the relic neutrinos. Suitably intense
sources of extremely energetic ($10^{21}$ -- $10^{25}$-eV) cosmic neutrinos
might therefore enable the determination of the absolute neutrino masses and
the flavor composition of the mass eigenstates. Several factors--other than
neutrino mass and composition--distort the absorption lines, however. We
analyze the influence of the time-evolution of the relic-neutrino density and
the consequences of neutrino decay. We consider the sensitivity of the
lineshape to the age and character of extremely energetic neutrino sources, and
to the thermal history of the Universe, reflected in the expansion rate. We
take into account Fermi motion arising from the thermal distribution of the
relic-neutrino gas. We also note the implications of Dirac vs. Majorana relics,
and briefly consider unconventional neutrino histories. We ask what kinds of
external information would enhance the potential of cosmic-neutrino absorption
spectroscopy, and estimate the sensitivity required to make the technique a
reality.
| [
{
"created": "Wed, 8 Dec 2004 23:25:53 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Barenboim",
"Gabriela",
""
],
[
"Requejo",
"Olga Mena",
""
],
[
"Quigg",
"Chris",
""
]
] | Annihilation of extremely energetic cosmic neutrinos on the relic-neutrino background can give rise to absorption lines at energies corresponding to formation of the electroweak gauge boson $Z^{0}$. The positions of the absorption dips are set by the masses of the relic neutrinos. Suitably intense sources of extremely energetic ($10^{21}$ -- $10^{25}$-eV) cosmic neutrinos might therefore enable the determination of the absolute neutrino masses and the flavor composition of the mass eigenstates. Several factors--other than neutrino mass and composition--distort the absorption lines, however. We analyze the influence of the time-evolution of the relic-neutrino density and the consequences of neutrino decay. We consider the sensitivity of the lineshape to the age and character of extremely energetic neutrino sources, and to the thermal history of the Universe, reflected in the expansion rate. We take into account Fermi motion arising from the thermal distribution of the relic-neutrino gas. We also note the implications of Dirac vs. Majorana relics, and briefly consider unconventional neutrino histories. We ask what kinds of external information would enhance the potential of cosmic-neutrino absorption spectroscopy, and estimate the sensitivity required to make the technique a reality. |
hep-ph/0205284 | Kingman Cheung | Kingman Cheung (NCTS) and Chung-Hsien Chou (Academia Sinica) | p-brane production in Fat brane or Universal extra dimension scenario | 12 pages | Phys.Rev. D66 (2002) 036008 | 10.1103/PhysRevD.66.036008 | NSC-NCTS-020524 | hep-ph | null | In models of large extra dimensions, the fundamental Planck scale can be as
low as TeV. Thus, in hadronic collisions interesting objects like black holes,
string balls, or $p$-branes can be produced. In scenarios of fat brane or
universal extra dimensions, the SM particles are allowed to propagate in the
extra spatial dimensions, which leads to the enhancement of production cross
sections of black holes and $p$-branes. Especially, the ratio of $p$-brane
cross section to the black hole cross section increases substantially, in
comparison with the original confined scenario. The ratio can be as large as
105 (for the case $n=7,m=5=p=r=k$).
| [
{
"created": "Fri, 24 May 2002 16:48:56 GMT",
"version": "v1"
}
] | 2009-11-07 | [
[
"Cheung",
"Kingman",
"",
"NCTS"
],
[
"Chou",
"Chung-Hsien",
"",
"Academia Sinica"
]
] | In models of large extra dimensions, the fundamental Planck scale can be as low as TeV. Thus, in hadronic collisions interesting objects like black holes, string balls, or $p$-branes can be produced. In scenarios of fat brane or universal extra dimensions, the SM particles are allowed to propagate in the extra spatial dimensions, which leads to the enhancement of production cross sections of black holes and $p$-branes. Especially, the ratio of $p$-brane cross section to the black hole cross section increases substantially, in comparison with the original confined scenario. The ratio can be as large as 105 (for the case $n=7,m=5=p=r=k$). |
1907.06561 | Chandan Mondal | Mohammad Ahmady, Chandan Mondal, Ruben Sandapen | Predicting the light-front holographic TMDs of the pion | 20 pages, 4 figures | Phys. Rev. D 100, 054005 (2019) | 10.1103/PhysRevD.100.054005 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We predict the twist-2 Transverse Momentum Dependent parton distribution
functions (TMDs) of the pion, namely the unpolarized quark TMD, $f_{1}(x,
k_\perp)$, and the transversely polarized quark TMD, also known as the
Boer-Mulders function, $h^\perp_{1}(x, k_\perp)$, using a holographic
light-front pion wavefunction with dynamical spin effects. These spin effects,
in conjunction with gluon rescattering, are crucial to predict a non-zero
holographic Boer-Mulders function. We investigate the use of a non-perturbative
SU(3) gluon rescattering kernel, thus going beyond the usual approximation of
perturbative U(1) gluons. We find that the non-perturbative color dynamics
offer a more promising way to describe the available lattice data on the
generalized Boer-Mulders shifts.
| [
{
"created": "Mon, 15 Jul 2019 16:05:13 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Sep 2019 05:12:04 GMT",
"version": "v2"
}
] | 2019-09-09 | [
[
"Ahmady",
"Mohammad",
""
],
[
"Mondal",
"Chandan",
""
],
[
"Sandapen",
"Ruben",
""
]
] | We predict the twist-2 Transverse Momentum Dependent parton distribution functions (TMDs) of the pion, namely the unpolarized quark TMD, $f_{1}(x, k_\perp)$, and the transversely polarized quark TMD, also known as the Boer-Mulders function, $h^\perp_{1}(x, k_\perp)$, using a holographic light-front pion wavefunction with dynamical spin effects. These spin effects, in conjunction with gluon rescattering, are crucial to predict a non-zero holographic Boer-Mulders function. We investigate the use of a non-perturbative SU(3) gluon rescattering kernel, thus going beyond the usual approximation of perturbative U(1) gluons. We find that the non-perturbative color dynamics offer a more promising way to describe the available lattice data on the generalized Boer-Mulders shifts. |
hep-ph/9601345 | A. Abada | Abdellatif Abada (Univ. Manchester) | On the Skyrme model prediction for the N-N spin-orbit force | uuencoded file (9 pages in TeX file + 1 figure postscript file); use
\psfig command | J.Phys.G22:L57-L64,1996 | 10.1088/0954-3899/22/5/001 | MC/TH 96/01 | hep-ph nucl-th | null | In the framework of the product ansatz as an approximation for the two-baryon
system we review in details the derivation of the isoscalar nucleon-nucleon
spin orbit potential coming from the sixth order term of the extended Skyrme
model. We show that the sixth order term contributes with a positive sign, as
is the case for the Skyrme term, contrary to the claims of Riska and
Schwesinger. Those authors considered only one part of the force due to the
sixth order term and omitted the second part which turns out to be the dominant
one. Our result is independent of the parameters of the model.
| [
{
"created": "Fri, 26 Jan 1996 15:10:00 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Abada",
"Abdellatif",
"",
"Univ. Manchester"
]
] | In the framework of the product ansatz as an approximation for the two-baryon system we review in details the derivation of the isoscalar nucleon-nucleon spin orbit potential coming from the sixth order term of the extended Skyrme model. We show that the sixth order term contributes with a positive sign, as is the case for the Skyrme term, contrary to the claims of Riska and Schwesinger. Those authors considered only one part of the force due to the sixth order term and omitted the second part which turns out to be the dominant one. Our result is independent of the parameters of the model. |
hep-ph/0206300 | Jonathan R. Ellis | John Ellis (CERN), Martti Raidal (CERN, Tallinn) and T. Yanagida
(CERN, Tokyo) | Observable Consequences of Partially Degenerate Leptogenesis | 15 pages, 3 eps figures | Phys.Lett.B546:228-236,2002 | 10.1016/S0370-2693(02)02691-6 | CERN-TH/2002-139 | hep-ph | null | In the context of the seesaw mechanism, it is natural that the large solar
and atmospheric neutrino mixing angles originate separately from large 2 by 2
mixings in the neutrino and charged-lepton sectors, respectively, and large
mixing in the neutrino couplings is in turn more plausible if two of the heavy
singlet neutrinos are nearly degenerate. We study the phenomenology of this
scenario, calculating leptogenesis by solving numerically the set of coupled
Boltzmann equations for out-of-equilibrium heavy singlet neutrino decays in the
minimal supersymmetric seesaw model. The near-degenerate neutrinos may weigh <
10^8 GeV, avoiding the cosmological gravitino problem. This scenario predicts
that Br(mu to e gamma) should be strongly suppressed, because of the small
singlet neutrino masses, whilst Br(tau to mu gamma) may be large enough to be
observable in B-factory or LHC experiments. If the light neutrino masses are
hierarchical, we predict that the neutrinoless double-beta decay parameter
m_{ee} is approximately sqrt{Delta m_{sol}^2} times sin^2 theta_{12}.
| [
{
"created": "Fri, 28 Jun 2002 13:06:01 GMT",
"version": "v1"
}
] | 2009-09-11 | [
[
"Ellis",
"John",
"",
"CERN"
],
[
"Raidal",
"Martti",
"",
"CERN, Tallinn"
],
[
"Yanagida",
"T.",
"",
"CERN, Tokyo"
]
] | In the context of the seesaw mechanism, it is natural that the large solar and atmospheric neutrino mixing angles originate separately from large 2 by 2 mixings in the neutrino and charged-lepton sectors, respectively, and large mixing in the neutrino couplings is in turn more plausible if two of the heavy singlet neutrinos are nearly degenerate. We study the phenomenology of this scenario, calculating leptogenesis by solving numerically the set of coupled Boltzmann equations for out-of-equilibrium heavy singlet neutrino decays in the minimal supersymmetric seesaw model. The near-degenerate neutrinos may weigh < 10^8 GeV, avoiding the cosmological gravitino problem. This scenario predicts that Br(mu to e gamma) should be strongly suppressed, because of the small singlet neutrino masses, whilst Br(tau to mu gamma) may be large enough to be observable in B-factory or LHC experiments. If the light neutrino masses are hierarchical, we predict that the neutrinoless double-beta decay parameter m_{ee} is approximately sqrt{Delta m_{sol}^2} times sin^2 theta_{12}. |
1006.2526 | Shinya Matsuzaki | Kazumoto Haba, Shinya Matsuzaki and Koichi Yamawaki | Holographic Techni-dilaton | 28 pages, 11 eps files, typos corrected, references added, Fig.1
corrected, some discussions added, to be published in PRD | Phys.Rev.D82:055007,2010 | 10.1103/PhysRevD.82.055007 | null | hep-ph hep-lat hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Techni-dilaton, a pseudo-Nambu-Goldstone boson of scale symmetry, was
predicted long ago in the Scale-invariant/Walking/Conformal Technicolor
(SWC-TC) as a remnant of the (approximate) scale symmetry associated with the
conformal fixed point, based on the conformal gauge dynamics of ladder
Schwinger-Dyson (SD) equation with non-running coupling. We study the
techni-dilaton as a flavor-singlet bound state of techni-fermions by including
the techni-gluon condensate (tGC) effect into the previous (bottom-up)
holographic approach to the SWC-TC, a deformation of the holographic QCD with
$\gamma_m \simeq 0$ by large anomalous dimension $\gamma_m \simeq 1$. With
including a bulk scalar field corresponding to the gluon condensate, we first
improve the Operator Product Expansion of the current correlators so as to
reproduce gluonic $1/Q^4$ term both in QCD and SWC-TC. We find in QCD about
$10\%$ (negative) contribution of gluon condensate to the $\rho$ meson mass. We
also calculate the oblique electroweak $S$-parameter in the presence of the
effect of the tGC and find that for the fixed value of $S$ the tGC effects
dramatically reduce the flavor-singlet scalar (techni-dilaton) mass $M_{\rm
TD}$ (in the unit of $F_\pi$), while the vector and axial-vector masses
$M_\rho$ and $M_{a_1}$ are rather insensitive to the tGC, where $F_\pi$ is the
decay constant of the techni-pion. If we use the range of values of tGC implied
by the ladder SD analysis of the non-perturbative scale anomaly in the large
$N_f$ QCD near the conformal window, the phenomenological constraint $S \simeq
0.1$ predicts the techni-dilaton mass $M_{\rm TD} \sim 600$ GeV which is within
reach of LHC discovery.
| [
{
"created": "Sun, 13 Jun 2010 11:16:29 GMT",
"version": "v1"
},
{
"created": "Tue, 15 Jun 2010 07:05:21 GMT",
"version": "v2"
},
{
"created": "Thu, 17 Jun 2010 07:42:54 GMT",
"version": "v3"
},
{
"created": "Thu, 5 Aug 2010 04:19:17 GMT",
"version": "v4"
}
] | 2014-11-21 | [
[
"Haba",
"Kazumoto",
""
],
[
"Matsuzaki",
"Shinya",
""
],
[
"Yamawaki",
"Koichi",
""
]
] | Techni-dilaton, a pseudo-Nambu-Goldstone boson of scale symmetry, was predicted long ago in the Scale-invariant/Walking/Conformal Technicolor (SWC-TC) as a remnant of the (approximate) scale symmetry associated with the conformal fixed point, based on the conformal gauge dynamics of ladder Schwinger-Dyson (SD) equation with non-running coupling. We study the techni-dilaton as a flavor-singlet bound state of techni-fermions by including the techni-gluon condensate (tGC) effect into the previous (bottom-up) holographic approach to the SWC-TC, a deformation of the holographic QCD with $\gamma_m \simeq 0$ by large anomalous dimension $\gamma_m \simeq 1$. With including a bulk scalar field corresponding to the gluon condensate, we first improve the Operator Product Expansion of the current correlators so as to reproduce gluonic $1/Q^4$ term both in QCD and SWC-TC. We find in QCD about $10\%$ (negative) contribution of gluon condensate to the $\rho$ meson mass. We also calculate the oblique electroweak $S$-parameter in the presence of the effect of the tGC and find that for the fixed value of $S$ the tGC effects dramatically reduce the flavor-singlet scalar (techni-dilaton) mass $M_{\rm TD}$ (in the unit of $F_\pi$), while the vector and axial-vector masses $M_\rho$ and $M_{a_1}$ are rather insensitive to the tGC, where $F_\pi$ is the decay constant of the techni-pion. If we use the range of values of tGC implied by the ladder SD analysis of the non-perturbative scale anomaly in the large $N_f$ QCD near the conformal window, the phenomenological constraint $S \simeq 0.1$ predicts the techni-dilaton mass $M_{\rm TD} \sim 600$ GeV which is within reach of LHC discovery. |
hep-ph/0602005 | Dominik Stockinger | Dominik St\"ockinger | Regularization of supersymmetric theories - recent progress | 5 pages, talk at the 7th International Symposium on Radiative
Corrections (RADCOR2005), Shonan Village, Japan, Oct. 2-7, 2005 | null | 10.1016/j.nuclphysbps.2006.03.018 | IPPP/06/08, DCPT/06/16 | hep-ph | null | General issues concerning the regularization of supersymmetric theories using
dimensional regularization and dimensional reduction are reviewed. Recent
progress on problems of dimensional reduction related to factorization,
supersymmetry, Higgs boson mass calculations, and mathematical consistency is
discussed.
| [
{
"created": "Wed, 1 Feb 2006 15:33:45 GMT",
"version": "v1"
}
] | 2009-11-11 | [
[
"Stöckinger",
"Dominik",
""
]
] | General issues concerning the regularization of supersymmetric theories using dimensional regularization and dimensional reduction are reviewed. Recent progress on problems of dimensional reduction related to factorization, supersymmetry, Higgs boson mass calculations, and mathematical consistency is discussed. |
1203.0724 | Jonathan Hall | J. M. M. Hall, V. Pascalutsa | Limitations of the heavy-baryon expansion as revealed by a pion-mass
dispersion relation | Accepted for publication in EPJ C. Made changes based on referee
comments: clarifying sentences to conclusion 1. of Section IV, beginning of
Section V, and new footnote in Section VI, page 8. Added more detailed
explanation in paragraph 4 of Section III. Added citations of Phys.Rev. D60,
034014, and Phys.Lett. B716, 338 | Eur.Phys.J.C72,2206,2012 | 10.1140/epjc/s10052-012-2206-8 | ADP-12-07/T774, MKPH-T-12-01 | hep-ph hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The chiral expansion of nucleon properties such as mass, magnetic moment, and
magnetic polarizability are investigated in the framework of chiral
perturbation theory, with and without the heavy-baryon expansion. The analysis
makes use of a pion-mass dispersion relation, which is shown to hold in both
frameworks. The dispersion relation allows an ultraviolet cutoff to be
implemented without compromising the symmetries. After renormalization, the
leading-order heavy-baryon loops demonstrate a stronger dependence on the
cutoff scale, which results in weakened convergence of the expansion. This
conclusion is tested against the recent results of lattice quantum
chromodynamics simulations for nucleon mass and isovector magnetic moment. In
the case of the polarizability, the situation is even more dramatic as the
heavy-baryon expansion is unable to reproduce large soft contributions to this
quantity. Clearly, the heavy-baryon expansion is not suitable for every
quantity.
| [
{
"created": "Sun, 4 Mar 2012 09:31:08 GMT",
"version": "v1"
},
{
"created": "Sat, 29 Sep 2012 08:01:03 GMT",
"version": "v2"
}
] | 2014-11-21 | [
[
"Hall",
"J. M. M.",
""
],
[
"Pascalutsa",
"V.",
""
]
] | The chiral expansion of nucleon properties such as mass, magnetic moment, and magnetic polarizability are investigated in the framework of chiral perturbation theory, with and without the heavy-baryon expansion. The analysis makes use of a pion-mass dispersion relation, which is shown to hold in both frameworks. The dispersion relation allows an ultraviolet cutoff to be implemented without compromising the symmetries. After renormalization, the leading-order heavy-baryon loops demonstrate a stronger dependence on the cutoff scale, which results in weakened convergence of the expansion. This conclusion is tested against the recent results of lattice quantum chromodynamics simulations for nucleon mass and isovector magnetic moment. In the case of the polarizability, the situation is even more dramatic as the heavy-baryon expansion is unable to reproduce large soft contributions to this quantity. Clearly, the heavy-baryon expansion is not suitable for every quantity. |
1612.05473 | Stefan Scherer | P. Bickert, P. Masjuan, S. Scherer | $\eta$-$\eta'$ Mixing in Large-$N_c$ Chiral Perturbation Theory | 39 pages, 8 figures | Phys. Rev. D 95, 054023 (2017) | 10.1103/PhysRevD.95.054023 | MITP/16-139 | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a calculation of the $\eta$-$\eta'$ mixing in the framework of
large-$N_c$ chiral perturbation theory. A general expression for the
$\eta$-$\eta'$ mixing at next-to-next-to-leading order (NNLO) is derived,
including higher-derivative terms up to fourth order in the four momentum,
kinetic and mass terms. In addition, the axial-vector decay constants of the
$\eta$-$\eta'$ system are determined at NNLO. The numerical analysis of the
results is performed successively at LO, NLO, and NNLO. We investigate the
influence of one-loop corrections, OZI-rule-violating parameters, and
$\mathcal{O}(N_c p^6)$ contact terms.
| [
{
"created": "Fri, 16 Dec 2016 14:10:37 GMT",
"version": "v1"
}
] | 2017-04-05 | [
[
"Bickert",
"P.",
""
],
[
"Masjuan",
"P.",
""
],
[
"Scherer",
"S.",
""
]
] | We present a calculation of the $\eta$-$\eta'$ mixing in the framework of large-$N_c$ chiral perturbation theory. A general expression for the $\eta$-$\eta'$ mixing at next-to-next-to-leading order (NNLO) is derived, including higher-derivative terms up to fourth order in the four momentum, kinetic and mass terms. In addition, the axial-vector decay constants of the $\eta$-$\eta'$ system are determined at NNLO. The numerical analysis of the results is performed successively at LO, NLO, and NNLO. We investigate the influence of one-loop corrections, OZI-rule-violating parameters, and $\mathcal{O}(N_c p^6)$ contact terms. |
hep-ph/0405118 | Bingsong Zou | B.S.Zou, F.Q.Wu, L.Li (Institute of High Energy Physics, Beijing),
D.V.Bugg (QMC, London) | Understanding I=2 pi-pi Interaction | Talk given at Hadron 03: 10th International Conference on Hadron
Spectroscopy, Aschaffenburg, Germany, 31 Aug - 6 Sep 2003 | null | 10.1063/1.1799730 | null | hep-ph | null | A correct understanding and description of the I=2 pi-pi S-wave interaction
is important for the extraction of the I=0 pi-pi S-wave interaction from
experimental data and for understanding the I=0 pi-pi S-wave interaction
theoretically. With t-channel rho, f2(1270) exchange and the pi pi -> rho rho
-> pi pi box diagram contribution, we reproduce the pi-pi isotensor S-wave and
D-wave scattering phase shifts and inelasticities up to 2.2 GeV quite well in a
K-matrix formalism.
| [
{
"created": "Thu, 13 May 2004 09:26:56 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Zou",
"B. S.",
"",
"Institute of High Energy Physics, Beijing"
],
[
"Wu",
"F. Q.",
"",
"Institute of High Energy Physics, Beijing"
],
[
"Li",
"L.",
"",
"Institute of High Energy Physics, Beijing"
],
[
"Bugg",
"D. V.",
"",
"QMC, London"
]
] | A correct understanding and description of the I=2 pi-pi S-wave interaction is important for the extraction of the I=0 pi-pi S-wave interaction from experimental data and for understanding the I=0 pi-pi S-wave interaction theoretically. With t-channel rho, f2(1270) exchange and the pi pi -> rho rho -> pi pi box diagram contribution, we reproduce the pi-pi isotensor S-wave and D-wave scattering phase shifts and inelasticities up to 2.2 GeV quite well in a K-matrix formalism. |
1201.0315 | Radovan Dermisek | Radovan Dermisek, Sung-Gi Kim and Aditi Raval | Z' near the Z-pole | 26 pages, 18 figures, minor modifications, one fig. added, results
unchanged | null | 10.1103/PhysRevD.85.075022 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a fit to precision electroweak data in the standard model extended
by an additional vector boson, Z', with suppressed couplings to the electron
compared to the Z boson, with couplings to the b-quark, and with mass close to
the mass of the Z boson. This scenario provides an excellent fit to
forward-backward asymmetry of the b-quark measured on the Z-pole and \pm 2 GeV
off the Z-pole, and to lepton asymmetry, A_e, obtained from the measurement of
left-right asymmetry for hadronic final states, and thus it removes the tension
in the determination of the weak mixing angle from these two measurements. It
also leads to a significant improvement in the total hadronic cross section on
the Z-pole and R_b measured at energies above the Z-pole. We explore in detail
properties of the Z' needed to explain the data and present a model for Z' with
required couplings. The model preserves standard model Yukawa couplings, it is
anomaly free and can be embedded into grand unified theories. It allows a
choice of parameters that does not generate any flavor violating couplings of
the Z' to standard model fermions. Out of standard model couplings, it only
negligibly modifies the left-handed bottom quark coupling to the Z boson and
the 3rd column of the CKM matrix. Modifications of standard model couplings in
the charged lepton sector are also negligible. It predicts an additional down
type quark, D, with mass in a few hundred GeV range, and an extra lepton
doublet, L, possibly much heavier than the D quark. We discuss signatures of
the Z' at the Large Hadron Collider and calculate the Z'b production cross
section which is the dominant production mechanism for the Z'.
| [
{
"created": "Sat, 31 Dec 2011 23:44:25 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Jan 2012 23:35:47 GMT",
"version": "v2"
}
] | 2013-05-30 | [
[
"Dermisek",
"Radovan",
""
],
[
"Kim",
"Sung-Gi",
""
],
[
"Raval",
"Aditi",
""
]
] | We present a fit to precision electroweak data in the standard model extended by an additional vector boson, Z', with suppressed couplings to the electron compared to the Z boson, with couplings to the b-quark, and with mass close to the mass of the Z boson. This scenario provides an excellent fit to forward-backward asymmetry of the b-quark measured on the Z-pole and \pm 2 GeV off the Z-pole, and to lepton asymmetry, A_e, obtained from the measurement of left-right asymmetry for hadronic final states, and thus it removes the tension in the determination of the weak mixing angle from these two measurements. It also leads to a significant improvement in the total hadronic cross section on the Z-pole and R_b measured at energies above the Z-pole. We explore in detail properties of the Z' needed to explain the data and present a model for Z' with required couplings. The model preserves standard model Yukawa couplings, it is anomaly free and can be embedded into grand unified theories. It allows a choice of parameters that does not generate any flavor violating couplings of the Z' to standard model fermions. Out of standard model couplings, it only negligibly modifies the left-handed bottom quark coupling to the Z boson and the 3rd column of the CKM matrix. Modifications of standard model couplings in the charged lepton sector are also negligible. It predicts an additional down type quark, D, with mass in a few hundred GeV range, and an extra lepton doublet, L, possibly much heavier than the D quark. We discuss signatures of the Z' at the Large Hadron Collider and calculate the Z'b production cross section which is the dominant production mechanism for the Z'. |
hep-ph/0505067 | Michael Andreas Schmidt | Manfred Lindner, Michael A. Schmidt, and Alexei Yu. Smirnov | Screening of Dirac flavor structure in the seesaw and neutrino mixing | 27 pages, 3 figures; references added, discussion of the E6 model
modified | JHEP0507:048,2005 | 10.1088/1126-6708/2005/07/048 | TUM-HEP-586/05 | hep-ph | null | We consider the mechanism of screening of the Dirac flavor structure in the
context of the double seesaw mechanism. As a consequence of screening, the
structure of the light neutrino mass matrix, m_\nu, is determined essentially
by the structure of the (Majorana) mass matrix, M_S, of new super-heavy (Planck
scale) neutral fermions S. We calculate effects of the renormalization group
running in order to investigate the stability of the screening mechanism with
respect to radiative corrections. We find that screening is stable in the
supersymmetric case, whereas in the standard model it is unstable for certain
structures of M_S. The screening mechanism allows us to reconcile the
(approximate) quark-lepton symmetry and the strong difference of the mixing
patterns in the quark and lepton sectors. It opens new possibilities to explain
a quasi-degenerate neutrino mass spectrum, special ``neutrino'' symmetries and
quark-lepton complementarity. Screening can emerge from certain flavor
symmetries or Grand Unification.
| [
{
"created": "Tue, 10 May 2005 16:12:13 GMT",
"version": "v1"
},
{
"created": "Mon, 23 May 2005 14:00:08 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Lindner",
"Manfred",
""
],
[
"Schmidt",
"Michael A.",
""
],
[
"Smirnov",
"Alexei Yu.",
""
]
] | We consider the mechanism of screening of the Dirac flavor structure in the context of the double seesaw mechanism. As a consequence of screening, the structure of the light neutrino mass matrix, m_\nu, is determined essentially by the structure of the (Majorana) mass matrix, M_S, of new super-heavy (Planck scale) neutral fermions S. We calculate effects of the renormalization group running in order to investigate the stability of the screening mechanism with respect to radiative corrections. We find that screening is stable in the supersymmetric case, whereas in the standard model it is unstable for certain structures of M_S. The screening mechanism allows us to reconcile the (approximate) quark-lepton symmetry and the strong difference of the mixing patterns in the quark and lepton sectors. It opens new possibilities to explain a quasi-degenerate neutrino mass spectrum, special ``neutrino'' symmetries and quark-lepton complementarity. Screening can emerge from certain flavor symmetries or Grand Unification. |
hep-ph/0608004 | Marek Karliner | Marek Karliner and Harry J. Lipkin | New Quark Relations for Hadron Masses and Magnetic Moments - A Challenge
for Explanation from QCD | Presentation improved, references added, typos corrected | Phys.Lett.B650:185-192,2007 | 10.1016/j.physletb.2007.04.063 | TAUP 2829/06, WIS/07/06-JULY-DPP, ANL-HEP-PR-06-56 | hep-ph | null | Prompted by the recent surprising results in QCD spectroscopy, we extend the
treatment of the constituent quark model showing that mass differences and
ratios have the same values when obtained from mesons and baryons. We obtain
several new successful relations involving hadrons containing two and three
strange quarks and hadrons containing heavy quarks and give a new prediction
regarding spin splitting between doubly charmed baryons. We provide numerical
evidence for an effective supersymmetry between mesons and baryons related by
replacing a light antiquark by a light diquark. We also obtain new relations
between quark magnetic moments and hadron masses. Limits of validity of this
approach and disagreements with experiment in properties of the Sigma and Xi
baryons are discussed as possible clues to a derivation from QCD.
| [
{
"created": "Tue, 1 Aug 2006 13:46:09 GMT",
"version": "v1"
},
{
"created": "Sun, 22 Oct 2006 23:05:15 GMT",
"version": "v2"
},
{
"created": "Fri, 4 May 2007 20:15:41 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Karliner",
"Marek",
""
],
[
"Lipkin",
"Harry J.",
""
]
] | Prompted by the recent surprising results in QCD spectroscopy, we extend the treatment of the constituent quark model showing that mass differences and ratios have the same values when obtained from mesons and baryons. We obtain several new successful relations involving hadrons containing two and three strange quarks and hadrons containing heavy quarks and give a new prediction regarding spin splitting between doubly charmed baryons. We provide numerical evidence for an effective supersymmetry between mesons and baryons related by replacing a light antiquark by a light diquark. We also obtain new relations between quark magnetic moments and hadron masses. Limits of validity of this approach and disagreements with experiment in properties of the Sigma and Xi baryons are discussed as possible clues to a derivation from QCD. |
0912.4498 | Jean-Philippe Lansberg | E. G. Ferreiro, F. Fleuret, J.P. Lansberg, A. Rakotozafindrabe | Centrality, Rapidity and Transverse-Momentum Dependence of Cold Nuclear
Matter Effects on J/Psi Production in d+Au, Cu+Cu and Au+Au Collisions at
sqrt(s_NN)=200 GeV | 12 pages, 14 figures, LaTeX. Version to appear in Phys. Rev. C: a few
typos corrected and one comment about the EPS08 nPDF parametrisation added | Phys.Rev.C81:064911,2010 | 10.1103/PhysRevC.81.064911 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have carried out a wide study of Cold Nuclear Matter (CNM) effects on
J/Psi production in d+Au, Cu+Cu and Au+Au collisions at sqrt(s_NN)=200 GeV. We
have studied the effects of three different gluon-shadowing parametrisations,
using the usual simplified kinematics for which the momentum of the gluon
recoiling against the J/Psi is neglected as well as an exact kinematics for a 2
-> 2 process, namely g+g -> J/psi+g as expected from LO pQCD. We have shown
that the rapidity distribution of the nuclear modification factor R_dAu, and
particularly its anti-shadowing peak, is systematically shifted toward larger
rapidities in the 2 -> 2 kinematics, irrespective of which shadowing
parametrisation is used. In turn, we have noted differences in the effective
final-state nuclear absorption necessary to fit the PHENIX d+Au data. Taking
advantage of our implementation of a 2 -> 2 kinematics, we have also computed
the transverse momentum dependence of the latter nuclear modification factor,
which cannot be predicted with the usual simplified kinematics. All the
corresponding observables have been computed for Cu+Cu and Au+Au collisions and
compared to the PHENIX and STAR data. Finally, we have extracted the effective
nuclear absorption from the recent measurements of R_CP in d+Au by the PHENIX
collaboration.
| [
{
"created": "Tue, 22 Dec 2009 20:09:10 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Jun 2010 22:52:31 GMT",
"version": "v2"
}
] | 2010-08-17 | [
[
"Ferreiro",
"E. G.",
""
],
[
"Fleuret",
"F.",
""
],
[
"Lansberg",
"J. P.",
""
],
[
"Rakotozafindrabe",
"A.",
""
]
] | We have carried out a wide study of Cold Nuclear Matter (CNM) effects on J/Psi production in d+Au, Cu+Cu and Au+Au collisions at sqrt(s_NN)=200 GeV. We have studied the effects of three different gluon-shadowing parametrisations, using the usual simplified kinematics for which the momentum of the gluon recoiling against the J/Psi is neglected as well as an exact kinematics for a 2 -> 2 process, namely g+g -> J/psi+g as expected from LO pQCD. We have shown that the rapidity distribution of the nuclear modification factor R_dAu, and particularly its anti-shadowing peak, is systematically shifted toward larger rapidities in the 2 -> 2 kinematics, irrespective of which shadowing parametrisation is used. In turn, we have noted differences in the effective final-state nuclear absorption necessary to fit the PHENIX d+Au data. Taking advantage of our implementation of a 2 -> 2 kinematics, we have also computed the transverse momentum dependence of the latter nuclear modification factor, which cannot be predicted with the usual simplified kinematics. All the corresponding observables have been computed for Cu+Cu and Au+Au collisions and compared to the PHENIX and STAR data. Finally, we have extracted the effective nuclear absorption from the recent measurements of R_CP in d+Au by the PHENIX collaboration. |
hep-ph/0010029 | Leszek Motyka | J. Kwiecinski and L. Motyka | Theoretical description of the total gamma*gamma* cross-section and its
confrontation with the LEP data on doubly tagged e+e- events | Latex, 14 pages and 8 eps figures | Eur.Phys.J.C18:343-351,2000 | 10.1007/s100520000535 | TSL/ISV-2000-0234 | hep-ph | null | We perform a detailed analysis of the total inelastic cross-section for
gamma*gamma* collisions. Different contributions coming from the quark box
diagram, reggeons, the soft and hard pomeron are included. The QCD pomeron
contribution contains a dominant part of subleading effects which reduces its
intercept and delays the onset of the asymptotic pomeron to high energies.
Estimates of the cross-section for doubly-tagged (e+e- to e+e- hadrons) events
are presented and compared with the existing LEP data. Good agreement between
the theoretical results and the experimental data is found. We also comment on
the extraction of the BFKL pomeron intercept from the available LEP
measurements.
| [
{
"created": "Wed, 4 Oct 2000 09:35:32 GMT",
"version": "v1"
}
] | 2009-01-07 | [
[
"Kwiecinski",
"J.",
""
],
[
"Motyka",
"L.",
""
]
] | We perform a detailed analysis of the total inelastic cross-section for gamma*gamma* collisions. Different contributions coming from the quark box diagram, reggeons, the soft and hard pomeron are included. The QCD pomeron contribution contains a dominant part of subleading effects which reduces its intercept and delays the onset of the asymptotic pomeron to high energies. Estimates of the cross-section for doubly-tagged (e+e- to e+e- hadrons) events are presented and compared with the existing LEP data. Good agreement between the theoretical results and the experimental data is found. We also comment on the extraction of the BFKL pomeron intercept from the available LEP measurements. |
1601.03576 | Daniil Gelfand | D. Gelfand, F. Hebenstreit, J. Berges | Early quark production and approach to chemical equilibrium | null | Phys. Rev. D 93, 085001 (2016) | 10.1103/PhysRevD.93.085001 | null | hep-ph hep-lat nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform real-time lattice simulations of out-of-equilibrium quark
production in non-Abelian gauge theory in 3+1-dimensions. Our simulations
include the backreaction of quarks onto the dynamical gluon sector, which is
particularly relevant for strongly correlated quarks. We observe fast
isotropization and universal behavior of quarks and gluons at weak coupling and
establish a quantitative connection to previous pure glue results. In order to
understand the strongly correlated regime, we perform simulations for a large
number of flavors and compare them to those obtained with two light quark
flavors. By doing this we are able to provide estimates of the chemical
equilibration time.
| [
{
"created": "Thu, 14 Jan 2016 12:16:29 GMT",
"version": "v1"
}
] | 2016-04-06 | [
[
"Gelfand",
"D.",
""
],
[
"Hebenstreit",
"F.",
""
],
[
"Berges",
"J.",
""
]
] | We perform real-time lattice simulations of out-of-equilibrium quark production in non-Abelian gauge theory in 3+1-dimensions. Our simulations include the backreaction of quarks onto the dynamical gluon sector, which is particularly relevant for strongly correlated quarks. We observe fast isotropization and universal behavior of quarks and gluons at weak coupling and establish a quantitative connection to previous pure glue results. In order to understand the strongly correlated regime, we perform simulations for a large number of flavors and compare them to those obtained with two light quark flavors. By doing this we are able to provide estimates of the chemical equilibration time. |
hep-ph/0011008 | null | V.A. Petrov | Hard Diffraction and Unitarity | 4 pages, LaTeX, no figures, Talk at the International Workshop "
Diffraction 2000" (Cetraro, Italy, 2-7 September 2000) | Nucl.Phys.Proc.Suppl. 99A (2001) 50-51 | 10.1016/S0920-5632(01)01305-6 | null | hep-ph | null | A short survey of the role of unitarity for hard diffractive cross-sections
is given
| [
{
"created": "Wed, 1 Nov 2000 12:26:05 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Petrov",
"V. A.",
""
]
] | A short survey of the role of unitarity for hard diffractive cross-sections is given |
hep-ph/9602440 | null | Y. S. Kim | Lorentz Boosts as Squeeze Transformations and the Parton Picture | 18 pages,LaTex,6 stone-age figures, presented at the Conference on
Fundamental Interaction of Elementary Particles, An Annual Meeting of
Particle and Nuclear Physics Division of the Russian Academy of Sciences
(October 1995),to be published in the J. of Moscow Physical Society. For a
uncompressed version, send an e-mail to <yskim@physics.umd.edu> with ITEP.TEX
on your Subject line | null | null | null | hep-ph hep-th nucl-th | null | It was shown by Gribov, Ioffe, Pomeranchuk in 1966 and by Ioffe in 1969 that
a space-time picture is needed for the Lorentz deformation of hadronic
interaction region. It is shown that this deformation is a squeeze
transformation. It is shown also that Feynman's parton picture emerges as a
consequence of Lorentz-squeezed hadrons in the quark model.
| [
{
"created": "Thu, 29 Feb 1996 15:50:46 GMT",
"version": "v1"
}
] | 2009-09-25 | [
[
"Kim",
"Y. S.",
""
]
] | It was shown by Gribov, Ioffe, Pomeranchuk in 1966 and by Ioffe in 1969 that a space-time picture is needed for the Lorentz deformation of hadronic interaction region. It is shown that this deformation is a squeeze transformation. It is shown also that Feynman's parton picture emerges as a consequence of Lorentz-squeezed hadrons in the quark model. |
1906.09010 | Juan Nieves Dr. | C. W. Xiao, J. Nieves and E. Oset | Prediction of hidden charm strange molecular baryon states with heavy
quark spin symmetry | 16 pages, 3 figures | Phys.Lett. B799 (2019) 135051 | 10.1016/j.physletb.2019.135051 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We have studied the meson-baryon $S-$wave interaction, using coupled
channels, in the isoscalar hidden-charm strange sector and $J^P = 1/2^-,3/2^-$
and $5/2^-$. We impose constraints of heavy quark spin symmetry in the
interaction and obtain the non vanishing matrix elements from an extension of
the local hidden gauge approach to the charm sector. The ultraviolet
divergences are renormalized using the same meson-baryon-loops regulator
previously employed in the non-strange hidden charm sector, where a good
reproduction of the properties of the newly discovered pentaquark states is
obtained. We obtain five states of $1/2^-$, four of $3/2^-$ and one of $5/2^-$,
which could be compared in the near future with forthcoming LHCb experiments.
The $5/2^-$, three of the $3/2^-$ and another three of the $1/2^-$ resonances
are originated from isoscalar $\bar D^{(*)}\Xi_c^\prime$ and $\bar
D^{(*)}\Xi_c^*$ interactions. They should be located just few MeV below the
corresponding thresholds (4446, 4513, 4588 and 4655 MeV), and would be
SU(3)-siblings of the isospin 1/2 $\bar D^{(*)} \Sigma_c^{(*)}$ quasi-bound
states previously found, and that provided a robust theoretical description of
the $P_c(4440)$, $P_c(4457)$ and $P_c(4312)$ LHCb exotic states. The another
two $1/2^-$ and $3/2^-$ states obtained in this work are result of the $\bar
D^{(*)}\Xi_c-D^{(*)}_s\Lambda_c$ coupled-channels isoscalar interaction, are
significantly broader than the others, with widths of the order of 15 MeV,
being $\bar D^{(*)}_s\Lambda_c$ the dominant decay channel.
| [
{
"created": "Fri, 21 Jun 2019 08:52:02 GMT",
"version": "v1"
}
] | 2020-01-09 | [
[
"Xiao",
"C. W.",
""
],
[
"Nieves",
"J.",
""
],
[
"Oset",
"E.",
""
]
] | We have studied the meson-baryon $S-$wave interaction, using coupled channels, in the isoscalar hidden-charm strange sector and $J^P = 1/2^-,3/2^-$ and $5/2^-$. We impose constraints of heavy quark spin symmetry in the interaction and obtain the non vanishing matrix elements from an extension of the local hidden gauge approach to the charm sector. The ultraviolet divergences are renormalized using the same meson-baryon-loops regulator previously employed in the non-strange hidden charm sector, where a good reproduction of the properties of the newly discovered pentaquark states is obtained. We obtain five states of $1/2^-$, four of $3/2^-$ and one of $5/2^-$, which could be compared in the near future with forthcoming LHCb experiments. The $5/2^-$, three of the $3/2^-$ and another three of the $1/2^-$ resonances are originated from isoscalar $\bar D^{(*)}\Xi_c^\prime$ and $\bar D^{(*)}\Xi_c^*$ interactions. They should be located just few MeV below the corresponding thresholds (4446, 4513, 4588 and 4655 MeV), and would be SU(3)-siblings of the isospin 1/2 $\bar D^{(*)} \Sigma_c^{(*)}$ quasi-bound states previously found, and that provided a robust theoretical description of the $P_c(4440)$, $P_c(4457)$ and $P_c(4312)$ LHCb exotic states. The another two $1/2^-$ and $3/2^-$ states obtained in this work are result of the $\bar D^{(*)}\Xi_c-D^{(*)}_s\Lambda_c$ coupled-channels isoscalar interaction, are significantly broader than the others, with widths of the order of 15 MeV, being $\bar D^{(*)}_s\Lambda_c$ the dominant decay channel. |
2306.07887 | Stefan Evans | Stefan Evans and Johann Rafelski | Improving Euler-Heisenberg-Schwinger effective action with dressed
photons | This article belongs to the special issue of Acta Physica Polonica A
printed in honor of Professor Iwo Bialynicki-Birula on the occasion of his
90th birthday (Ed. Tomasz Sowinski, DOI:10.12693/APhysPolA.143.S0) | Acta Phys. Pol. A 143, S13 (2023) | 10.12693/APhysPolA.143.S13 | null | hep-ph hep-th nucl-th quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We implement a longstanding proposal by Weisskopf to apply virtual
polarization corrections to the in/out external fields in study of the
Euler-Heisenberg-Schwinger effective action. Our approach requires
distinguishing the electromagnetic and polarization fields based on
mathematical tools developed by Bia{\l}ynicki-Birula, originally for the
Born-Infeld action. Our solution is expressed as a differential equation where
the one-loop effective action serves as input. As a first result of our
approach, we recover the higher-order one-cut reducible loop diagrams
discovered by Gies and Karbstein.
| [
{
"created": "Tue, 13 Jun 2023 16:28:06 GMT",
"version": "v1"
}
] | 2023-06-16 | [
[
"Evans",
"Stefan",
""
],
[
"Rafelski",
"Johann",
""
]
] | We implement a longstanding proposal by Weisskopf to apply virtual polarization corrections to the in/out external fields in study of the Euler-Heisenberg-Schwinger effective action. Our approach requires distinguishing the electromagnetic and polarization fields based on mathematical tools developed by Bia{\l}ynicki-Birula, originally for the Born-Infeld action. Our solution is expressed as a differential equation where the one-loop effective action serves as input. As a first result of our approach, we recover the higher-order one-cut reducible loop diagrams discovered by Gies and Karbstein. |
1405.7213 | Zhen-Hua Zhang | Z.-H. Zhang, G. L\"u, and K.-W. Wei | Probing the mass degeneracy of particles with different spins | null | Chinese Physics C 39(2015) 5: 053101 | 10.1088/1674-1137/39/5/053101 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The spin is an important property of a particle. Although it is unlikely to
happen, there is still a possibility that two particle with different spins
share similar masses. In this paper, we propose a method to probe this kind of
mass degeneracy of particles with different spins. We will use the cascade
decay $B^+\to X(3872)K^+$, $X(3872)\to D^+D^-$ to explain our method. It can be
seen that the possible mass degeneracy of $X(3872)$ can lead interesting
behavior in the corresponding cascade decay.
| [
{
"created": "Wed, 28 May 2014 12:07:17 GMT",
"version": "v1"
},
{
"created": "Mon, 2 Jun 2014 02:39:03 GMT",
"version": "v2"
}
] | 2015-03-16 | [
[
"Zhang",
"Z. -H.",
""
],
[
"Lü",
"G.",
""
],
[
"Wei",
"K. -W.",
""
]
] | The spin is an important property of a particle. Although it is unlikely to happen, there is still a possibility that two particle with different spins share similar masses. In this paper, we propose a method to probe this kind of mass degeneracy of particles with different spins. We will use the cascade decay $B^+\to X(3872)K^+$, $X(3872)\to D^+D^-$ to explain our method. It can be seen that the possible mass degeneracy of $X(3872)$ can lead interesting behavior in the corresponding cascade decay. |
1905.10327 | Joe Davighi | B. C. Allanach, Joe Davighi | Naturalising the Third Family Hypercharge Model for Neutral Current
$B-$Anomalies | 13 pages, 6 figures. More accurate cross-section calculation taking
off-shell Z' effects into account. Little qualitative difference, although
the lower limit for the Z prime mass is slightly larger (now 1.2 TeV rather
than 0.8 TeV as in the published version). Two minus sign typos in the
definition of the Lagrangian have also been corrected. (Previous version
accepted for publication in EPJC.) | null | 10.1140/epjc/s10052-019-7414-z | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider a deformation of the Third Family Hypercharge Model, which
arguably makes the model more natural. Additional non-zero charges of the
spontaneously broken, family-dependent $U(1)_F$ gauge symmetry are assigned to
the second family leptons, and the third family leptons' charges are deformed
away from their hypercharges in such a way that the $U(1)_F$ gauge symmetry
remains anomaly-free. Second family $U(1)_F$ lepton charges allow a $Z^\prime$
coupling to muons without having to assume large charged lepton mixing, which
risks violating tight lepton flavour violation bounds. In this deformed
version, only the bottom and top Yukawa couplings are generated at the
renormalisable level, whereas the tauon Yukawa coupling is absent. The
$Z^\prime$ mediates a beyond the Standard Model contribution to an effective
$(\bar b s) (\bar \mu \mu)$ vertex in the combination $C_9=-9C_{10}$ and is
able to fit the apparent discrepancy between Standard Model predictions in
flavour changing neutral-current $B-$meson decays and their measurements,
whilst simultaneously avoiding current constraints from direct $Z^\prime$
searches and other measurements, when $1.2\ \text{TeV} < M_{Z^\prime} < 12.5\
\text{TeV}$.
| [
{
"created": "Fri, 24 May 2019 16:37:09 GMT",
"version": "v1"
},
{
"created": "Mon, 21 Oct 2019 14:59:48 GMT",
"version": "v2"
},
{
"created": "Tue, 28 Jan 2020 15:08:52 GMT",
"version": "v3"
},
{
"created": "Mon, 8 Jun 2020 18:15:51 GMT",
"version": "v4"
},
{
"created": "Thu, 30 Jul 2020 20:03:05 GMT",
"version": "v5"
}
] | 2020-08-03 | [
[
"Allanach",
"B. C.",
""
],
[
"Davighi",
"Joe",
""
]
] | We consider a deformation of the Third Family Hypercharge Model, which arguably makes the model more natural. Additional non-zero charges of the spontaneously broken, family-dependent $U(1)_F$ gauge symmetry are assigned to the second family leptons, and the third family leptons' charges are deformed away from their hypercharges in such a way that the $U(1)_F$ gauge symmetry remains anomaly-free. Second family $U(1)_F$ lepton charges allow a $Z^\prime$ coupling to muons without having to assume large charged lepton mixing, which risks violating tight lepton flavour violation bounds. In this deformed version, only the bottom and top Yukawa couplings are generated at the renormalisable level, whereas the tauon Yukawa coupling is absent. The $Z^\prime$ mediates a beyond the Standard Model contribution to an effective $(\bar b s) (\bar \mu \mu)$ vertex in the combination $C_9=-9C_{10}$ and is able to fit the apparent discrepancy between Standard Model predictions in flavour changing neutral-current $B-$meson decays and their measurements, whilst simultaneously avoiding current constraints from direct $Z^\prime$ searches and other measurements, when $1.2\ \text{TeV} < M_{Z^\prime} < 12.5\ \text{TeV}$. |
1412.6478 | Stefan H\"oche | Stefan H\"oche, Silvan Kuttimalai, Steffen Schumann, Frank Siegert | Beyond Standard Model calculations with Sherpa | 13 pages, 5 figures | Eur.Phys.J. C75 (2015) 135 | 10.1140/epjc/s10052-015-3338-4 | SLAC-PUB 16170, IPPP/14/105, DCPT/14/210, MCNET-14-35 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a fully automated framework as part of the Sherpa event generator
for the computation of tree-level cross sections in beyond Standard Model
scenarios, making use of model information given in the Universal FeynRules
Output format. Elementary vertices are implemented into C++ code automatically
and provided to the matrix-element generator Comix at runtime. Widths and
branching ratios for unstable particles are computed from the same building
blocks. The corresponding decays are simulated with spin correlations. Parton
showers, QED radiation and hadronization are added by Sherpa, providing a full
simulation of arbitrary BSM processes at the hadron level.
| [
{
"created": "Fri, 19 Dec 2014 18:43:47 GMT",
"version": "v1"
},
{
"created": "Thu, 18 Jun 2015 04:49:32 GMT",
"version": "v2"
}
] | 2015-06-19 | [
[
"Höche",
"Stefan",
""
],
[
"Kuttimalai",
"Silvan",
""
],
[
"Schumann",
"Steffen",
""
],
[
"Siegert",
"Frank",
""
]
] | We present a fully automated framework as part of the Sherpa event generator for the computation of tree-level cross sections in beyond Standard Model scenarios, making use of model information given in the Universal FeynRules Output format. Elementary vertices are implemented into C++ code automatically and provided to the matrix-element generator Comix at runtime. Widths and branching ratios for unstable particles are computed from the same building blocks. The corresponding decays are simulated with spin correlations. Parton showers, QED radiation and hadronization are added by Sherpa, providing a full simulation of arbitrary BSM processes at the hadron level. |
2205.12119 | Oleg Andreev | Oleg Andreev | Towards a Stringy Description for the $Q\bar Q q\bar q$-Quark System | 22 pages, many figures; v2: typos corrected; v3: improved discussion,
references added; v4: typo corrected; v5: the sign in (3.23) corrected | null | 10.1103/PhysRevD.106.066002 | LMU-ASC 11/22 | hep-ph hep-lat hep-th nucl-th | http://creativecommons.org/licenses/by/4.0/ | For the case of two light flavors we propose the stringy description of the
system made of one heavy and one light quark-antiquark pair, with the aim of
exploring the two lower-lying Born-Oppenheimer potentials as a function of a
separation of the heavy quark-antiquark pair. Our analysis reveals three
critical separations related to the processes of string reconnection, breaking
and junction annihilation. In particular, for the ground state potential only
the process of string reconnection matters. We find that a tetraquark state
makes the dominant contribution to the potential of the first excited state at
small separations, and this is the big difference with the $QQ\bar q\bar
q$-quark system where it does so to the ground state potential. Another big
difference is the emergence of the full diquark picture $[Qq][\bar Q\bar q]$
rather than the partial picture $QQ[\bar q\bar q]$ for the tetraquark state. On
the other hand, the scales of string junction annihilation, below which the
systems can be thought of mainly as the compact tetraquarks, are very close for
both cases and become almost the same if the phenomenological rule
$E_{QQ}=\frac{1}{2} E_{Q\bar Q}$ holds. The same is also true for the screening
lengths whose values are in agreement with lattice QCD.
| [
{
"created": "Tue, 24 May 2022 14:48:44 GMT",
"version": "v1"
},
{
"created": "Mon, 30 May 2022 12:06:09 GMT",
"version": "v2"
},
{
"created": "Mon, 22 Aug 2022 14:56:20 GMT",
"version": "v3"
},
{
"created": "Fri, 10 Feb 2023 15:58:50 GMT",
"version": "v4"
},
{
"created": "Sun, 25 Jun 2023 15:38:29 GMT",
"version": "v5"
}
] | 2023-06-27 | [
[
"Andreev",
"Oleg",
""
]
] | For the case of two light flavors we propose the stringy description of the system made of one heavy and one light quark-antiquark pair, with the aim of exploring the two lower-lying Born-Oppenheimer potentials as a function of a separation of the heavy quark-antiquark pair. Our analysis reveals three critical separations related to the processes of string reconnection, breaking and junction annihilation. In particular, for the ground state potential only the process of string reconnection matters. We find that a tetraquark state makes the dominant contribution to the potential of the first excited state at small separations, and this is the big difference with the $QQ\bar q\bar q$-quark system where it does so to the ground state potential. Another big difference is the emergence of the full diquark picture $[Qq][\bar Q\bar q]$ rather than the partial picture $QQ[\bar q\bar q]$ for the tetraquark state. On the other hand, the scales of string junction annihilation, below which the systems can be thought of mainly as the compact tetraquarks, are very close for both cases and become almost the same if the phenomenological rule $E_{QQ}=\frac{1}{2} E_{Q\bar Q}$ holds. The same is also true for the screening lengths whose values are in agreement with lattice QCD. |
hep-ph/0504112 | Vladimir Galkin | D. Ebert, R. N. Faustov, V. O. Galkin | Masses of heavy baryons in the relativistic quark model | 13 pages, 2 figures, version published in Phys. Rev. D | Phys.Rev. D72 (2005) 034026 | 10.1103/PhysRevD.72.034026 | HU-EP-05/18 | hep-ph hep-ex | null | The masses of the ground state heavy baryons consisting of two light (u,d,s)
and one heavy (c,b) quarks are calculated in the heavy-quark--light-diquark
approximation within the constituent quark model. The light quarks, forming the
diquark, and the light diquark in the baryon are treated completely
relativistically. The expansion in v/c up to the second order is used only for
the heavy (b and c) quarks. The diquark-gluon interaction is taken modified by
the form factor describing the light diquark structure in terms of the diquark
wave functions. An overall reasonable agreement of the obtained predictions
with available experimental data and previous theoretical results is found.
| [
{
"created": "Thu, 14 Apr 2005 14:04:20 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Aug 2005 09:00:11 GMT",
"version": "v2"
}
] | 2009-11-11 | [
[
"Ebert",
"D.",
""
],
[
"Faustov",
"R. N.",
""
],
[
"Galkin",
"V. O.",
""
]
] | The masses of the ground state heavy baryons consisting of two light (u,d,s) and one heavy (c,b) quarks are calculated in the heavy-quark--light-diquark approximation within the constituent quark model. The light quarks, forming the diquark, and the light diquark in the baryon are treated completely relativistically. The expansion in v/c up to the second order is used only for the heavy (b and c) quarks. The diquark-gluon interaction is taken modified by the form factor describing the light diquark structure in terms of the diquark wave functions. An overall reasonable agreement of the obtained predictions with available experimental data and previous theoretical results is found. |
0812.3942 | Sedigheh Deldar | Sedigheh Deldar, Shahnoosh Rafibakhsh | The effect of fluctuations of the vortex core size on the static
potentials evaluated by the thick center vortex model | Contribution presented at the conference "Quark Confinement and the
Hadron Spectrum VIII", Mainz, Germany, Sept. 1-6, 2008 | PoS Confinement8:053,2008 | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | By varying the vortex core size of the thick center vortex model, we have
studied the short distance potentials between static sources. It has been found
that fluctuations of the vortex core size lead to Coulombic behavior.
Furthermore, we discuss the influence of such fluctuations on Casimir scaling
for both the Coulombic and the linear part of the potential.
| [
{
"created": "Sat, 20 Dec 2008 06:49:59 GMT",
"version": "v1"
}
] | 2009-06-25 | [
[
"Deldar",
"Sedigheh",
""
],
[
"Rafibakhsh",
"Shahnoosh",
""
]
] | By varying the vortex core size of the thick center vortex model, we have studied the short distance potentials between static sources. It has been found that fluctuations of the vortex core size lead to Coulombic behavior. Furthermore, we discuss the influence of such fluctuations on Casimir scaling for both the Coulombic and the linear part of the potential. |
hep-ph/9601313 | Stefan Groote | S. Groote, J.G. K"orner and M.M. Tung | Polar Angle Dependence of the Alignment Polarization of Quarks Produced
in e^+e^- Annihilation | 33 pages, LaTeX, 4 figures are included in PostScript format | Z.Phys. C74 (1997) 615-629 | null | MZ-TH/95-19, FTUV/95-52, IFIC/95-54 | hep-ph | null | We calculate one-loop radiative QCD corrections to the three polarized and
unpolarized structure functions that determine the beam-quark polar angle
dependence of the alignment (or longitudinal) polarization of light and heavy
quarks produced in e^+e^- annihilations. We present analytical and numerical
results for the alignment polarization and its polar angle dependence. We
discuss in some detail the zero-mass limit of our results and the role of the
anomalous spin-flip contributions to the polarization observables in the
zero-mass limit. Our discussion includes transverse and longitudinal beam
polarization effects.
| [
{
"created": "Wed, 24 Jan 1996 05:45:26 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Groote",
"S.",
""
],
[
"K\"orner",
"J. G.",
""
],
[
"Tung",
"M. M.",
""
]
] | We calculate one-loop radiative QCD corrections to the three polarized and unpolarized structure functions that determine the beam-quark polar angle dependence of the alignment (or longitudinal) polarization of light and heavy quarks produced in e^+e^- annihilations. We present analytical and numerical results for the alignment polarization and its polar angle dependence. We discuss in some detail the zero-mass limit of our results and the role of the anomalous spin-flip contributions to the polarization observables in the zero-mass limit. Our discussion includes transverse and longitudinal beam polarization effects. |
hep-ph/0206187 | Zheng Xiaoping | Zheng Xiaoping, Yang Shuhua, Li Jiarong | Bulk viscosity of interacting strange quark matter | 8 pages, 3 figures | Phys.Lett. B548 (2002) 29-34 | null | null | hep-ph | null | The quarks are regarded as quasiparticles, which acquire an effective mass
generated by the interaction with the other quarks of the dense system. The
bulk viscosity is re-expressed in the case of interacting strange quark matter.
We find that the viscosity is a few ~ tens times larger than that of
non-interacting quark gas due to the small correction of medium effect to the
equation of state. The limiting spins of strange stars will rise so
significantly that the pulsars with shorter period may exist.
| [
{
"created": "Thu, 20 Jun 2002 07:35:20 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Aug 2002 12:29:50 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Xiaoping",
"Zheng",
""
],
[
"Shuhua",
"Yang",
""
],
[
"Jiarong",
"Li",
""
]
] | The quarks are regarded as quasiparticles, which acquire an effective mass generated by the interaction with the other quarks of the dense system. The bulk viscosity is re-expressed in the case of interacting strange quark matter. We find that the viscosity is a few ~ tens times larger than that of non-interacting quark gas due to the small correction of medium effect to the equation of state. The limiting spins of strange stars will rise so significantly that the pulsars with shorter period may exist. |
hep-ph/0009015 | P. Aurenche | P. Aurenche | Photon and lepton pair production in a quark-gluon plasma | 10 pages, 7 postscript figures, based on talks given in July 2000 at
QCD 00, Montpellier, France, and at ICHEP2000, Osaka, Japan | Nucl.Phys.Proc.Suppl. 96 (2001) 179-183 | 10.1016/S0920-5632(01)01128-8 | LAPTH-Conf-810/2000 | hep-ph | null | We discuss the production of real or virtual photons in a quark-gluon plasma.
| [
{
"created": "Sat, 2 Sep 2000 16:30:00 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Aurenche",
"P.",
""
]
] | We discuss the production of real or virtual photons in a quark-gluon plasma. |
2012.06842 | Sourav Pal | Neelima Agarwal, Ayan Mukhopadhyay, Sourav Pal, Anurag Tripathi | Power corrections to event shapes using eikonal dressed gluon
exponentiation | 13 pages, 1 figure, one section added, conclusions remain unchanged,
matches published version | null | 10.1007/JHEP03(2021)155 | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Event shapes are classical tools for the determination of the strong coupling
and for the study of hadronization effects in electron-positron annihilation.
In the context of analytical studies, hadronization corrections take the form
of power-suppressed contributions to the cross-section, which can be extracted
from the perturbative ambiguity of Borel-resummed distributions. We propose a
simplified version of the well-established method of Dressed Gluon
Exponentiation (DGE), which we call Eikonal DGE (EDGE), which determines all
dominant power corrections to event shapes by means of strikingly elementary
calculations. We believe our method can be generalized to hadronic event shapes
and jet shapes of relevance for LHC physics.
| [
{
"created": "Sat, 12 Dec 2020 15:37:32 GMT",
"version": "v1"
},
{
"created": "Mon, 21 Jun 2021 09:10:38 GMT",
"version": "v2"
}
] | 2021-06-22 | [
[
"Agarwal",
"Neelima",
""
],
[
"Mukhopadhyay",
"Ayan",
""
],
[
"Pal",
"Sourav",
""
],
[
"Tripathi",
"Anurag",
""
]
] | Event shapes are classical tools for the determination of the strong coupling and for the study of hadronization effects in electron-positron annihilation. In the context of analytical studies, hadronization corrections take the form of power-suppressed contributions to the cross-section, which can be extracted from the perturbative ambiguity of Borel-resummed distributions. We propose a simplified version of the well-established method of Dressed Gluon Exponentiation (DGE), which we call Eikonal DGE (EDGE), which determines all dominant power corrections to event shapes by means of strikingly elementary calculations. We believe our method can be generalized to hadronic event shapes and jet shapes of relevance for LHC physics. |
hep-ph/9707436 | Steven Abel | Steven Abel and Ben Allanach | The Quasi-Fixed MSSM | 19 Pages plain latex; includes 6 eps figures. References and comments
added. Version to appear in Phys.Lett.B | Phys.Lett. B415 (1997) 371-382 | 10.1016/S0370-2693(97)01274-4 | RAL-TR-97-032, ULB-TH-97/14 | hep-ph | null | The infra-red fixed points are determined for all the parameters of the MSSM.
They dominate the renormalisation group running when the top-Yukawa is in the
quasi-fixed point regime (i.e. large at the GUT scale). We examine this
behaviour analytically, by solving the full set of one-loop renormalisation
group equations in the approximation that the electroweak contributions are
negligible, and also numerically. We find the quasi-fixed points for the
top-quark trilinear couplings; A_{U_{\alpha 3}} = A_{U_{3\alpha}}=-0.59 m_g
independently of the input parameters at the unification scale. All the
remaining parameters are significantly focused towards their true fixed points
at the weak scale. We examine how this increases the predictivity of the MSSM
in this regime.
| [
{
"created": "Wed, 23 Jul 1997 12:40:20 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Aug 1997 10:40:32 GMT",
"version": "v2"
},
{
"created": "Fri, 19 Sep 1997 14:51:40 GMT",
"version": "v3"
}
] | 2009-10-30 | [
[
"Abel",
"Steven",
""
],
[
"Allanach",
"Ben",
""
]
] | The infra-red fixed points are determined for all the parameters of the MSSM. They dominate the renormalisation group running when the top-Yukawa is in the quasi-fixed point regime (i.e. large at the GUT scale). We examine this behaviour analytically, by solving the full set of one-loop renormalisation group equations in the approximation that the electroweak contributions are negligible, and also numerically. We find the quasi-fixed points for the top-quark trilinear couplings; A_{U_{\alpha 3}} = A_{U_{3\alpha}}=-0.59 m_g independently of the input parameters at the unification scale. All the remaining parameters are significantly focused towards their true fixed points at the weak scale. We examine how this increases the predictivity of the MSSM in this regime. |
hep-ph/0109262 | Christos Kokorelis | C. Kokorelis | Constraint supersymmetry Breaking and Non-perturbative Effects in String
Theory | No Changes, 6 pages, no figures, To appear in the proceedings of the
conference, "Recent Developements in General Relativity, Genoa 2000",
SIGRAV2000, Genoa (Italy), September 2000. Based on talks given at SUSY2K,
CERN, Geneva, 26/6-1/7 and at SIGRAV2000 | "Recent Developments in General Relativity-Genoa 2000", edited by
R. Cianci, R. Collina, M. Francaviglia and P. Fre, Springer-Verlag, Milano
(2002) 429 | null | FTUAM-01/18; IFT-UAM/CSIC-01-27 | hep-ph | null | We discuss supersymmetry breaking mechanisms at the level of low energy N=1
effective heterotic superstring actions that exhibit $SL(2,Z)_T$ target space
modular duality or $SL(2,Z)_S$ strong-weak coupling duality. The allowed
superpotential forms use the assumption that the source of non-perturbative
effects is not specified and as a result represent the most general
parametrization of non-perturbative effects. The minimum values of the limits
on the parameters in the superpotential may correspond to vacua with vanishing
cosmological constant.
| [
{
"created": "Thu, 27 Sep 2001 10:56:37 GMT",
"version": "v1"
},
{
"created": "Thu, 22 Nov 2001 19:06:05 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Kokorelis",
"C.",
""
]
] | We discuss supersymmetry breaking mechanisms at the level of low energy N=1 effective heterotic superstring actions that exhibit $SL(2,Z)_T$ target space modular duality or $SL(2,Z)_S$ strong-weak coupling duality. The allowed superpotential forms use the assumption that the source of non-perturbative effects is not specified and as a result represent the most general parametrization of non-perturbative effects. The minimum values of the limits on the parameters in the superpotential may correspond to vacua with vanishing cosmological constant. |
hep-ph/0210300 | Vahagn Nazaryan | Vahagn Nazaryan | Evaluating matrix elements relevant to some Lorenz violating operators | 4 pages, 3 figures, RevTex, minor changes | Phys.Rev. D67 (2003) 017704 | 10.1103/PhysRevD.67.017704 | WM-02-110 | hep-ph | null | Carlson, Carone and Lebed have derived the Feynman rules for a consistent
formulation of noncommutative QCD. The results they obtained were used to
constrain the noncommutativity parameter in Lorentz violating noncommutative
field theories. However, their constraint depended upon an estimate of the
matrix element of the quark level operator (gamma.p - m) in a nucleon. In this
paper we calculate the matrix element of (gamma.p - m), using a variety of
confinement potential models. Our results are within an order of magnitude
agreement with the estimate made by Carlson et al. The constraints placed on
the noncommutativity parameter were very strong, and are still quite severe
even if weakened by an order of magnitude.
| [
{
"created": "Tue, 22 Oct 2002 18:48:16 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Nov 2002 20:10:57 GMT",
"version": "v2"
}
] | 2009-11-07 | [
[
"Nazaryan",
"Vahagn",
""
]
] | Carlson, Carone and Lebed have derived the Feynman rules for a consistent formulation of noncommutative QCD. The results they obtained were used to constrain the noncommutativity parameter in Lorentz violating noncommutative field theories. However, their constraint depended upon an estimate of the matrix element of the quark level operator (gamma.p - m) in a nucleon. In this paper we calculate the matrix element of (gamma.p - m), using a variety of confinement potential models. Our results are within an order of magnitude agreement with the estimate made by Carlson et al. The constraints placed on the noncommutativity parameter were very strong, and are still quite severe even if weakened by an order of magnitude. |
2209.04239 | Andrea Beraudo | Andrea Beraudo, Arturo De Pace, Daniel Pablos Alfonso, Francesco
Prino, Marco Monteno, Marzia Nardi | Heavy-flavor meson and baryon production in high-energy nucleus-nucleus
collisions | SQM 2022 proceedings | null | 10.1051/epjconf/202327602009 | null | hep-ph nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a new model for the description of heavy-flavor hadronization in
relativistic heavy-ion collisions. We explore its effect on the charmed hadron
yields and kinematic distributions once the latter is applied at the end of
transport calculations used to simulate the propagation of heavy quarks in the
deconfined fireball produced in the collision. The model is based on the
formation of color-singlet clusters through the recombination of charm quarks
with light antiquarks or diquarks from the same fluid cell. This local
mechanism of color neutralization leads to a strong space-momentum correlation,
which provides a substantial enhancement of charmed baryon production and of
the collective flow of all charmed hadrons.
| [
{
"created": "Fri, 9 Sep 2022 10:52:53 GMT",
"version": "v1"
}
] | 2023-03-22 | [
[
"Beraudo",
"Andrea",
""
],
[
"De Pace",
"Arturo",
""
],
[
"Alfonso",
"Daniel Pablos",
""
],
[
"Prino",
"Francesco",
""
],
[
"Monteno",
"Marco",
""
],
[
"Nardi",
"Marzia",
""
]
] | We present a new model for the description of heavy-flavor hadronization in relativistic heavy-ion collisions. We explore its effect on the charmed hadron yields and kinematic distributions once the latter is applied at the end of transport calculations used to simulate the propagation of heavy quarks in the deconfined fireball produced in the collision. The model is based on the formation of color-singlet clusters through the recombination of charm quarks with light antiquarks or diquarks from the same fluid cell. This local mechanism of color neutralization leads to a strong space-momentum correlation, which provides a substantial enhancement of charmed baryon production and of the collective flow of all charmed hadrons. |
hep-ph/9905545 | Stefano Frixione | S. Frixione (CERN) | Heavy quark photoproduction | 4 pages Latex; npb.sty included. Talk given at DIS99, 19 - 23 April
1999, Zeuthen, DE | Nucl.Phys.Proc.Suppl. 79 (1999) 399-402 | 10.1016/S0920-5632(99)00734-3 | CERN-TH/99-157 | hep-ph | null | I present a review of selected topics in the computation of heavy flavour
cross sections in photon-hadron collisions.
| [
{
"created": "Sun, 30 May 1999 08:55:49 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Frixione",
"S.",
"",
"CERN"
]
] | I present a review of selected topics in the computation of heavy flavour cross sections in photon-hadron collisions. |
1912.00379 | Takaaki Nomura | Takaaki Nomura, Hiroshi Okada, Sudhanwa Patra | An Inverse Seesaw model with $A_4$-modular symmetry | 21 pages, 6 figures | null | null | KIAS-P19067, APCTP Pre2019 - 026 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We discuss an inverse seesaw model based on right-handed fermion specific
$U(1)$ gauge symmetry and $A_4$-modular symmetry. These symmetries forbid
unnecessary terms and restrict structures of Yukawa interactions which are
relevant to inverse seesaw mechanism. Then we can obtain some predictions in
neutrino sector such as Dirac-CP phase and sum of neutrino mass, which are
shown by our numerical analysis. Besides the relation among masses of heavy
pseudo-Dirac neutrino can be obtained since it is also restricted by the
modular symmetry. We also discuss implications to lepton flavor violation and
collider physics in our model.
| [
{
"created": "Sun, 1 Dec 2019 10:39:14 GMT",
"version": "v1"
}
] | 2019-12-03 | [
[
"Nomura",
"Takaaki",
""
],
[
"Okada",
"Hiroshi",
""
],
[
"Patra",
"Sudhanwa",
""
]
] | We discuss an inverse seesaw model based on right-handed fermion specific $U(1)$ gauge symmetry and $A_4$-modular symmetry. These symmetries forbid unnecessary terms and restrict structures of Yukawa interactions which are relevant to inverse seesaw mechanism. Then we can obtain some predictions in neutrino sector such as Dirac-CP phase and sum of neutrino mass, which are shown by our numerical analysis. Besides the relation among masses of heavy pseudo-Dirac neutrino can be obtained since it is also restricted by the modular symmetry. We also discuss implications to lepton flavor violation and collider physics in our model. |
2404.06008 | Waqas Ahmed | Waqas Ahmed, Maria Mehmood, Mansoor Ur Rehman and Umer Zubair | Inflation, Proton Decay and Gravitational Waves from Metastable Strings
in $SU(4)_C \times SU(2)_L \times U(1)_R$ Model | 10 pages, 7 figures | null | null | null | hep-ph gr-qc | http://creativecommons.org/licenses/by-nc-sa/4.0/ | We present a realistic supersymmetric $\mu$-hybrid inflation model within the
framework of $SU(4)_C \times SU(2)_L \times U(1)_R$ gauge symmetry, wherein the
symmetry breaking $SU(4)_C \times SU(2)_L \times U(1)_R\rightarrow
SU(3)_C\times SU(2)_L \times U(1)_{B-L}\times U(1)_R$ occurs before observable
inflation, effectively eliminating topologically stable primordial monopoles.
Subsequent breaking of $U(1)_{B-L} \times U(1)_R \rightarrow U(1)_Y$ after
inflation leads to the formation of superheavy metastable cosmic strings (CSs),
capable of producing a stochastic gravitational wave background (SGWB)
consistent with the recent PTA data. Moreover, the scalar spectral index $n_s$
and the tensor-to-scalar ratio $r$ align with Planck 2018 observations. A
consistent scenario for reheating and non-thermal leptogenesis is employed to
explain the observed matter content of the universe. Finally, the embedding of
$G_{421}$ into the Pati-Salam gauge symmetry $G_{422}$ is briefly discussed,
predicting potentially observable proton decay rates detectable at facilities
such as Hyper Kamiokande and DUNE.
| [
{
"created": "Tue, 9 Apr 2024 04:28:06 GMT",
"version": "v1"
}
] | 2024-04-10 | [
[
"Ahmed",
"Waqas",
""
],
[
"Mehmood",
"Maria",
""
],
[
"Rehman",
"Mansoor Ur",
""
],
[
"Zubair",
"Umer",
""
]
] | We present a realistic supersymmetric $\mu$-hybrid inflation model within the framework of $SU(4)_C \times SU(2)_L \times U(1)_R$ gauge symmetry, wherein the symmetry breaking $SU(4)_C \times SU(2)_L \times U(1)_R\rightarrow SU(3)_C\times SU(2)_L \times U(1)_{B-L}\times U(1)_R$ occurs before observable inflation, effectively eliminating topologically stable primordial monopoles. Subsequent breaking of $U(1)_{B-L} \times U(1)_R \rightarrow U(1)_Y$ after inflation leads to the formation of superheavy metastable cosmic strings (CSs), capable of producing a stochastic gravitational wave background (SGWB) consistent with the recent PTA data. Moreover, the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$ align with Planck 2018 observations. A consistent scenario for reheating and non-thermal leptogenesis is employed to explain the observed matter content of the universe. Finally, the embedding of $G_{421}$ into the Pati-Salam gauge symmetry $G_{422}$ is briefly discussed, predicting potentially observable proton decay rates detectable at facilities such as Hyper Kamiokande and DUNE. |
1612.09264 | Jay Tasson | Jay D. Tasson | Gravitational Searches for Lorentz Violation with Matter and
Astrophysics | Presented at the Seventh Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, June 20-24, 2016 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This contribution to the CPT'16 proceedings summarizes recent tests of
Lorentz violation in the pure-gravity sector with cosmic rays and reviews
recent progress in matter-gravity couplings.
| [
{
"created": "Thu, 29 Dec 2016 19:46:49 GMT",
"version": "v1"
}
] | 2016-12-30 | [
[
"Tasson",
"Jay D.",
""
]
] | This contribution to the CPT'16 proceedings summarizes recent tests of Lorentz violation in the pure-gravity sector with cosmic rays and reviews recent progress in matter-gravity couplings. |
2109.14102 | Nikolaos Kidonakis | Nikolaos Kidonakis | Three-loop soft anomalous dimensions in QCD | 10 pages; contribution to Radcor-LoopFest 2021 | SciPost Phys. Proc. 7, 046 (2022) | 10.21468/SciPostPhysProc.7.046 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I present results for soft anomalous dimensions through three loops for many
QCD processes. In particular, I give detailed expressions for soft anomalous
dimensions in various processes with electroweak and Higgs bosons as well as
single top quarks and top-antitop pairs.
| [
{
"created": "Tue, 28 Sep 2021 23:43:17 GMT",
"version": "v1"
}
] | 2022-08-08 | [
[
"Kidonakis",
"Nikolaos",
""
]
] | I present results for soft anomalous dimensions through three loops for many QCD processes. In particular, I give detailed expressions for soft anomalous dimensions in various processes with electroweak and Higgs bosons as well as single top quarks and top-antitop pairs. |
1605.08727 | Tarso Franarin | Tarso Franarin and Malcolm Fairbairn | Reducing the Solar Neutrino Background Using Polarised Helium-3 | Matches version accepted in Physical Review D | Phys. Rev. D 94, 053004 (2016) | 10.1103/PhysRevD.94.053004 | KCL-PH-TH/2016-31 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Future dark matter detectors plan to have sensitivities such that solar
neutrinos will start to become a problematic background. In this work we show
that a polarised helium-3 detector would in principle be able to eliminate 98%
of these events when the orientation of the polarisation axis is antiparallel
to the direction of the Sun. We comment on the possible improvement in
sensitivity of dark matter direct detection experiments due to this effect and
the feasibility of building such a detector.
| [
{
"created": "Fri, 27 May 2016 17:47:46 GMT",
"version": "v1"
},
{
"created": "Sun, 4 Sep 2016 09:35:26 GMT",
"version": "v2"
}
] | 2016-09-21 | [
[
"Franarin",
"Tarso",
""
],
[
"Fairbairn",
"Malcolm",
""
]
] | Future dark matter detectors plan to have sensitivities such that solar neutrinos will start to become a problematic background. In this work we show that a polarised helium-3 detector would in principle be able to eliminate 98% of these events when the orientation of the polarisation axis is antiparallel to the direction of the Sun. We comment on the possible improvement in sensitivity of dark matter direct detection experiments due to this effect and the feasibility of building such a detector. |
hep-ph/0311370 | A. A. Arkhipov | A.A. Arkhipov | On the Recent Results of E835 Experiment at FNAL | Latex2e, 6 pages, 3 tables; revtex4, 5 pages, 3 tables, version
submitted to PRL | null | null | null | hep-ph cond-mat hep-ex nucl-ex | null | In this note we briefly concern several recent results of E835 Experiment at
FNAL that are discussed in the framework of unified picture on hadronic spectra
elaborated in our early works. It has been established that new E835
Collaboration results provided an additional excellent confirmation of our
theoretical conception.
| [
{
"created": "Fri, 28 Nov 2003 17:25:36 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Feb 2004 19:13:18 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Arkhipov",
"A. A.",
""
]
] | In this note we briefly concern several recent results of E835 Experiment at FNAL that are discussed in the framework of unified picture on hadronic spectra elaborated in our early works. It has been established that new E835 Collaboration results provided an additional excellent confirmation of our theoretical conception. |
1510.05895 | Jaume Tarr\'us | Nora Brambilla, Gast\~ao Krein, Jaume Tarr\'us Castell\`a and Antonio
Vairo | Long-range properties of $1S$ bottomonium states | 24 pages, 10 figures. Journal version | Phys. Rev. D 93, 054002 (2016) | 10.1103/PhysRevD.93.054002 | TUM-EFT 70/15 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the framework of weakly-coupled pNRQCD, we derive, first, an analytical
expression for the chromo-polarizability of $1S$-bottomonium states in
agreement with previous determinations. Then we use the QCD trace anomaly to
obtain the two-pion production amplitude for the chromo-polarizability operator
and match the result to a chiral effective field theory with $1S$-bottomonium
states and pions as degrees-of-freedom. In this chiral effective field theory
we compute some long-range properties of the $1S$ bottomonium generated by the
pion coupling such as the leading chiral logarithm to the $1S$-bottomonium mass
and the van der Waals potential between two $1S$-bottomonium states. Both
results improve on previously known expressions.
| [
{
"created": "Tue, 20 Oct 2015 13:48:07 GMT",
"version": "v1"
},
{
"created": "Mon, 18 Jan 2016 20:46:14 GMT",
"version": "v2"
},
{
"created": "Wed, 2 Mar 2016 15:20:58 GMT",
"version": "v3"
}
] | 2016-03-09 | [
[
"Brambilla",
"Nora",
""
],
[
"Krein",
"Gastão",
""
],
[
"Castellà",
"Jaume Tarrús",
""
],
[
"Vairo",
"Antonio",
""
]
] | In the framework of weakly-coupled pNRQCD, we derive, first, an analytical expression for the chromo-polarizability of $1S$-bottomonium states in agreement with previous determinations. Then we use the QCD trace anomaly to obtain the two-pion production amplitude for the chromo-polarizability operator and match the result to a chiral effective field theory with $1S$-bottomonium states and pions as degrees-of-freedom. In this chiral effective field theory we compute some long-range properties of the $1S$ bottomonium generated by the pion coupling such as the leading chiral logarithm to the $1S$-bottomonium mass and the van der Waals potential between two $1S$-bottomonium states. Both results improve on previously known expressions. |
2008.11792 | Maria Catalina Espinoza Hernandez | C. Espinoza and M. Mondrag\'on | Prospects of Indirect Detection for the Heavy S3 Dark Doublet | 17 pages plus references, 7 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present an analysis of the Dark S3 model in the heavy DM mass region, this
model features an S3 symmetric extension of the scalar sector of the SM
including a scalar $SU(2)$ doublet dark matter candidate. We use publicly
available tools to compute, in addition to conventional physical constraints on
the parameter space of the model, the Sommerfeld enhancement factors for the
present day annihilation cross section and the likelihood profile for a
simulation of an observation run by the Cherenkov Telescope Array of the Coma
Berenices dwarf galaxy. Our results disfavour masses above $\sim$5 TeV mainly
because of overproduction of dark matter not consistent with the relic
abundance observations; we also find a moderately large region with masses in
between 1.2 and 4.9 TeV which predict the correct value of the DM relic and in
addition have a light scalar with the characteristics of the SM Higgs boson
(i.e. within the decoupling limit akin to the THDM). Comparison of our results
with model independent exclusion curves from HESS and other CTA simulations
show that these limits fall short only an order of magnitude in the value of
the annihilation cross section in order to exclude the best fit point of the
model.
| [
{
"created": "Wed, 26 Aug 2020 20:22:35 GMT",
"version": "v1"
}
] | 2020-08-28 | [
[
"Espinoza",
"C.",
""
],
[
"Mondragón",
"M.",
""
]
] | We present an analysis of the Dark S3 model in the heavy DM mass region, this model features an S3 symmetric extension of the scalar sector of the SM including a scalar $SU(2)$ doublet dark matter candidate. We use publicly available tools to compute, in addition to conventional physical constraints on the parameter space of the model, the Sommerfeld enhancement factors for the present day annihilation cross section and the likelihood profile for a simulation of an observation run by the Cherenkov Telescope Array of the Coma Berenices dwarf galaxy. Our results disfavour masses above $\sim$5 TeV mainly because of overproduction of dark matter not consistent with the relic abundance observations; we also find a moderately large region with masses in between 1.2 and 4.9 TeV which predict the correct value of the DM relic and in addition have a light scalar with the characteristics of the SM Higgs boson (i.e. within the decoupling limit akin to the THDM). Comparison of our results with model independent exclusion curves from HESS and other CTA simulations show that these limits fall short only an order of magnitude in the value of the annihilation cross section in order to exclude the best fit point of the model. |
1801.10595 | Eduardo Rojas | Richard H. Benavides, Luis Mu\~noz, William A. Ponce, Oscar
Rodr\'iguez, Eduardo Rojas | Electroweak couplings and LHC constraints on alternative $Z^{\prime}$
models in $E_6$ | null | null | 10.1142/S0217751X18502068 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We report the most general expression for the chiral charges of a $Z'$ gauge
boson coming from an $E_6$ unification model, as a function of the electroweak
parameters and the charges of the $U(1)$ factors in the chain of subgroups.
These charges are valid for an arbitrary Higgs sector and only depend on the
branching rules of the $E_6$ fundamental representation and the corresponding
rules for the fermionic representations of their subgroups. By assuming $E_6$
unification, the renormalization group equations~(RGE) allow us to calculate
the electroweak parameters at low energies for most of the chains of subgroups
in $E_6$. From RGE and unitary conditions, we show that at low energies there
must be a mixing between the gauge boson of the standard model hypercharge and
the $Z'$. From this, it is possible to delimit the preferred region in the
parameter space for a breaking pattern in $E_6$. In general, without
unification, it is not viable to determine this region; however, for some
models and under certain assumptions, it is possible to limit the corresponding
parameter space. By using the most recent upper limits on the cross-section of
extra gauge vector bosons $Z'$ decaying into dileptons from the ATLAS data at
13~TeV with accumulated luminosities of 36.1~fb$^{-1}$ and 13.3~fb$^{-1}$, we
report the 95$\%$ C.L. lower limits on the $Z'$ mass for the typical $E_6$
benchmark models. We also show the contours in the 95\% C.L. of the $Z'$ mass
bounds for the entire parameter space of $E_6$.
| [
{
"created": "Wed, 31 Jan 2018 18:34:56 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Jan 2019 20:44:33 GMT",
"version": "v2"
}
] | 2019-01-30 | [
[
"Benavides",
"Richard H.",
""
],
[
"Muñoz",
"Luis",
""
],
[
"Ponce",
"William A.",
""
],
[
"Rodríguez",
"Oscar",
""
],
[
"Rojas",
"Eduardo",
""
]
] | We report the most general expression for the chiral charges of a $Z'$ gauge boson coming from an $E_6$ unification model, as a function of the electroweak parameters and the charges of the $U(1)$ factors in the chain of subgroups. These charges are valid for an arbitrary Higgs sector and only depend on the branching rules of the $E_6$ fundamental representation and the corresponding rules for the fermionic representations of their subgroups. By assuming $E_6$ unification, the renormalization group equations~(RGE) allow us to calculate the electroweak parameters at low energies for most of the chains of subgroups in $E_6$. From RGE and unitary conditions, we show that at low energies there must be a mixing between the gauge boson of the standard model hypercharge and the $Z'$. From this, it is possible to delimit the preferred region in the parameter space for a breaking pattern in $E_6$. In general, without unification, it is not viable to determine this region; however, for some models and under certain assumptions, it is possible to limit the corresponding parameter space. By using the most recent upper limits on the cross-section of extra gauge vector bosons $Z'$ decaying into dileptons from the ATLAS data at 13~TeV with accumulated luminosities of 36.1~fb$^{-1}$ and 13.3~fb$^{-1}$, we report the 95$\%$ C.L. lower limits on the $Z'$ mass for the typical $E_6$ benchmark models. We also show the contours in the 95\% C.L. of the $Z'$ mass bounds for the entire parameter space of $E_6$. |
hep-ph/9902461 | B. Ananthanarayan | B. Ananthanarayan (Bangalore), and P. B\"uttiker (J\"ulich) | Pion-Pion Scattering in Chiral Perturbation and Dispersion Relation
Theories | Invited talk at the "Frontiers of Fundamental Physics" Symposium, B.
M. Birla Science Centre, Hyderabad, India, December 30, 1998- January 1,
1999, Plain latex (to be run twice), 20 pages | null | null | IISc-CTS/2/99, FZJ-IKP(TH)-1999-05 | hep-ph | null | Chiral perturbation theory, the low energy effective theory of the strong
interactions for the light pseudoscalar degrees of freedom, is based on
effective Lagrangian techniques and is an expansion in the powers of the
external momenta and the powers of the quark masses, which correct the
soft-pion theorems. Our primary emphasis will be on the problem of $\pi\pi$
scattering. After briefly reviewing these features and some results, we review
some features of $\pi-N$ scattering.
| [
{
"created": "Thu, 25 Feb 1999 07:04:34 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Ananthanarayan",
"B.",
"",
"Bangalore"
],
[
"Büttiker",
"P.",
"",
"Jülich"
]
] | Chiral perturbation theory, the low energy effective theory of the strong interactions for the light pseudoscalar degrees of freedom, is based on effective Lagrangian techniques and is an expansion in the powers of the external momenta and the powers of the quark masses, which correct the soft-pion theorems. Our primary emphasis will be on the problem of $\pi\pi$ scattering. After briefly reviewing these features and some results, we review some features of $\pi-N$ scattering. |
hep-ph/0004265 | Osman Yilmaz | T. Barakat (Near East University) | The Radiative Leptonic $B_{c}\to \tau\bar{\nu_{\tau}}\gamma$ Decay in
Two Higgs Doublet Model | null | Mod.Phys.Lett.A16:775,2001; Mod.Phys.Lett.A16:775-788,2001 | 10.1142/S0217732301003735 | null | hep-ph | null | The radiative leptonic $B_{c}\to\tau\bar{\nu_{\tau}}\gamma$ decay is analysed
in context of 2HDM. It is shown that with large values of $tan\beta$, the
contributions of Model II to the decay rate exceeds considerably the Standard
Model ones, while the contributions of Model I overlap with the Standard Model
predictions.
| [
{
"created": "Fri, 28 Apr 2000 08:47:18 GMT",
"version": "v1"
}
] | 2011-03-23 | [
[
"Barakat",
"T.",
"",
"Near East University"
]
] | The radiative leptonic $B_{c}\to\tau\bar{\nu_{\tau}}\gamma$ decay is analysed in context of 2HDM. It is shown that with large values of $tan\beta$, the contributions of Model II to the decay rate exceeds considerably the Standard Model ones, while the contributions of Model I overlap with the Standard Model predictions. |
1711.02382 | Valery Zamiralov | V.S.Zamiralov | Unitary symmetry of DDK sum rules for hadron photoproduction on octet
baryons | 7 pages, 1 figure | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Dubnicka-Dubnickova-Kuraev (DDK) sum rules are considered. It is shown that
integrals over differences of the total photoproduction cross-sections on octet
baryons could be understood in terms of unitary symmetry approach. All the DDK
sum rules for these quantities are expressed in terms of only three parameters.
| [
{
"created": "Tue, 7 Nov 2017 10:35:40 GMT",
"version": "v1"
}
] | 2017-11-08 | [
[
"Zamiralov",
"V. S.",
""
]
] | Dubnicka-Dubnickova-Kuraev (DDK) sum rules are considered. It is shown that integrals over differences of the total photoproduction cross-sections on octet baryons could be understood in terms of unitary symmetry approach. All the DDK sum rules for these quantities are expressed in terms of only three parameters. |
1504.02893 | Ashutosh Alok | Ashutosh Kumar Alok, Subhashish Banerjee, S. Uma Sankar | Re-examining sin(2beta) and Delta m(d) from evolution of B(d) mesons
with decoherence | Version accepted for publication in Physics Letters B | Phys. Lett. B 749 (2015) 94 | 10.1016/j.physletb.2015.07.061 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the time evolution of neutral meson systems, a perfect quantum coherence
is usually assumed. The important quantities of the B(d) system, such as sin
(2beta) and Delta m(d), are determined under this assumption. However, the
meson system interacts with its environment. This interaction can lead to
decoherence in the mesons even before they decay. In our formalism this
decoherence is modelled by a single parameter lambda. It is desirable to
re-examine the procedures of determination of sin(2beta) and Delta m(d) in
meson systems with decoherence. We find that the present values of these two
quantities are modulated by lambda. Re-analysis of B(d) data from B-factories
and LHCb can lead to a clean determination of lambda, sin(2beta) and Delta
m(d).
| [
{
"created": "Sat, 11 Apr 2015 16:23:44 GMT",
"version": "v1"
},
{
"created": "Thu, 30 Jul 2015 08:20:55 GMT",
"version": "v2"
}
] | 2015-08-05 | [
[
"Alok",
"Ashutosh Kumar",
""
],
[
"Banerjee",
"Subhashish",
""
],
[
"Sankar",
"S. Uma",
""
]
] | In the time evolution of neutral meson systems, a perfect quantum coherence is usually assumed. The important quantities of the B(d) system, such as sin (2beta) and Delta m(d), are determined under this assumption. However, the meson system interacts with its environment. This interaction can lead to decoherence in the mesons even before they decay. In our formalism this decoherence is modelled by a single parameter lambda. It is desirable to re-examine the procedures of determination of sin(2beta) and Delta m(d) in meson systems with decoherence. We find that the present values of these two quantities are modulated by lambda. Re-analysis of B(d) data from B-factories and LHCb can lead to a clean determination of lambda, sin(2beta) and Delta m(d). |
2311.01613 | Craig Roberts | H.-Y. Xing, Z.-Q. Yao, B.-L. Li, D. Binosi, Z.-F. Cui and C. D.
Roberts | Developing predictions for pion fragmentation functions | 9 pages, 4 figures | null | null | NJU-INP 079/23 | hep-ph hep-ex hep-lat nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Exploiting crossing symmetry, the hadron scale pion valence quark
distribution function is used to predict the kindred elementary valence quark
fragmentation function (FF). This function defines the kernel of a quark jet
fragmentation equation, which is solved to obtain the full pion FFs. After
evolution to a scale typical of FF fits to data, the results for quark FFs are
seen to compare favourably with such fits. However, the gluon FF is markedly
different. Notably, although FF evolution equations do not themselves guarantee
momentum conservation, inclusion of a gluon FF which, for four quark flavours,
distributes roughly 11% of the total light-front momentum fraction, is
sufficient to restore momentum conservation under evolution. Overall,
significant uncertainty is attached to FFs determined via fits to data; hence,
the features of the predictions described herein could potentially provide
useful guidance for future such studies.
| [
{
"created": "Thu, 2 Nov 2023 21:51:42 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Nov 2023 10:29:58 GMT",
"version": "v2"
}
] | 2023-11-07 | [
[
"Xing",
"H. -Y.",
""
],
[
"Yao",
"Z. -Q.",
""
],
[
"Li",
"B. -L.",
""
],
[
"Binosi",
"D.",
""
],
[
"Cui",
"Z. -F.",
""
],
[
"Roberts",
"C. D.",
""
]
] | Exploiting crossing symmetry, the hadron scale pion valence quark distribution function is used to predict the kindred elementary valence quark fragmentation function (FF). This function defines the kernel of a quark jet fragmentation equation, which is solved to obtain the full pion FFs. After evolution to a scale typical of FF fits to data, the results for quark FFs are seen to compare favourably with such fits. However, the gluon FF is markedly different. Notably, although FF evolution equations do not themselves guarantee momentum conservation, inclusion of a gluon FF which, for four quark flavours, distributes roughly 11% of the total light-front momentum fraction, is sufficient to restore momentum conservation under evolution. Overall, significant uncertainty is attached to FFs determined via fits to data; hence, the features of the predictions described herein could potentially provide useful guidance for future such studies. |
1204.0802 | Michael Trott | Hyun Min Lee, Veronica Sanz, and Michael Trott | Hitting sbottom in natural SUSY | 18 pages, 8 figures,v2 refs added, JHEP version | JHEP05(2012)139 | 10.1007/JHEP05(2012)139 | CERN_PH_TH/2012-083 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compare the experimental prospects of direct stop and sbottom pair
production searches at the LHC. Such searches for stops are of great interest
as they directly probe for states that are motivated by the SUSY solution to
the hierarchy problem of the Higgs mass parameter - leading to a "Natural" SUSY
spectrum. Noting that sbottom searches are less experimentally challenging and
scale up in reach directly with the improvement on b-tagging algorithms, we
discuss the interplay of small TeV scale custodial symmetry violation with
sbottom direct pair production searches as a path to obtaining strong sub-TeV
constraints on stops in a natural SUSY scenario. We argue that if a weak scale
natural SUSY spectrum does not exist within the reach of LHC, then hopes for
such a spectrum for large regions of parameter space should sbottom out.
Conversely, the same arguments make clear that a discovery of such a spectrum
is likely to proceed in a sbottom up manner.
| [
{
"created": "Tue, 3 Apr 2012 20:27:27 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Jun 2012 08:59:04 GMT",
"version": "v2"
}
] | 2015-06-04 | [
[
"Lee",
"Hyun Min",
""
],
[
"Sanz",
"Veronica",
""
],
[
"Trott",
"Michael",
""
]
] | We compare the experimental prospects of direct stop and sbottom pair production searches at the LHC. Such searches for stops are of great interest as they directly probe for states that are motivated by the SUSY solution to the hierarchy problem of the Higgs mass parameter - leading to a "Natural" SUSY spectrum. Noting that sbottom searches are less experimentally challenging and scale up in reach directly with the improvement on b-tagging algorithms, we discuss the interplay of small TeV scale custodial symmetry violation with sbottom direct pair production searches as a path to obtaining strong sub-TeV constraints on stops in a natural SUSY scenario. We argue that if a weak scale natural SUSY spectrum does not exist within the reach of LHC, then hopes for such a spectrum for large regions of parameter space should sbottom out. Conversely, the same arguments make clear that a discovery of such a spectrum is likely to proceed in a sbottom up manner. |
0811.4752 | Wei-Ning Zhang | Li-Li Yu (1), M. J. Efaaf (2), Yan-Yu Ren (1), Wei-Ning Zhang (1,2)
((1)Harbin Institute of Technology; (2)Dalian University of Technology) | Interferometry signatures for QCD first-order phase transition in heavy
ion collisions at GSI-FAIR energies | 16 pages, 4 figures | null | 10.1088/0256-307X/27/2/022501 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the technique of quantum transport of the interfering pair we examine
the Hanbury-Brown-Twiss (HBT) interferometry signatures for the
particle-emitting sources of pions and kaons produced in the heavy ion
collisions at GSI-FAIR energies. The evolution of the sources is described by
relativistic hydrodynamics with the system equation of state of the first-order
phase transition from quark-gluon plasma (QGP) to hadronic matter. We use
quantum probability amplitudes in a path-integral formalism to calculate the
two-particle correlation functions, where the effects of particle decay and
multiple scattering are taken into consideration. We find that the HBT radii of
kaons are smaller than those of pions for the same initial conditions. Both the
HBT radii of pions and kaons increase with the system initial energy density.
The HBT lifetimes of the pion and kaon sources are sensitive to the initial
energy density. They are significantly prolonged when the initial energy
density is tuned to the phase boundary between the QGP and mixed phase. This
prolongations of the HBT lifetimes of pions and kaons may likely be observed in
the heavy ion collisions with an incident energy in the GSI-FAIR energy range.
| [
{
"created": "Fri, 28 Nov 2008 17:07:24 GMT",
"version": "v1"
}
] | 2015-05-13 | [
[
"Yu",
"Li-Li",
"",
"Harbin Institute of Technology;"
],
[
"Efaaf",
"M. J.",
"",
"Dalian University of Technology"
],
[
"Ren",
"Yan-Yu",
"",
"Harbin Institute of Technology;"
],
[
"Zhang",
"Wei-Ning",
"",
"Harbin Institute of Technology;",
"Dalian University of Technology"
]
] | Using the technique of quantum transport of the interfering pair we examine the Hanbury-Brown-Twiss (HBT) interferometry signatures for the particle-emitting sources of pions and kaons produced in the heavy ion collisions at GSI-FAIR energies. The evolution of the sources is described by relativistic hydrodynamics with the system equation of state of the first-order phase transition from quark-gluon plasma (QGP) to hadronic matter. We use quantum probability amplitudes in a path-integral formalism to calculate the two-particle correlation functions, where the effects of particle decay and multiple scattering are taken into consideration. We find that the HBT radii of kaons are smaller than those of pions for the same initial conditions. Both the HBT radii of pions and kaons increase with the system initial energy density. The HBT lifetimes of the pion and kaon sources are sensitive to the initial energy density. They are significantly prolonged when the initial energy density is tuned to the phase boundary between the QGP and mixed phase. This prolongations of the HBT lifetimes of pions and kaons may likely be observed in the heavy ion collisions with an incident energy in the GSI-FAIR energy range. |
2201.01120 | Raghav Chaturvedi Dr. | Vikas Patel, Raghav Chaturvedi, A. K. Rai | Spectroscopic Properties of $\mathit {B}$ and $\mathit {B_s}$ meson
using Screened Potential | null | null | null | null | hep-ph | http://creativecommons.org/licenses/by-nc-nd/4.0/ | Inspired by the recent observations of $B$ and $B_s$ meson states at
LHCb\cite{Aaij:2020hcw} we calculate the masses of ground, orbitally, and
radially excited states. Also, we estimate the mixing parameters, decay
constant, leptonic decay width, and corresponding branching ratios, as well as
electromagnetic transition widths. ${\cal{O}}\left(\frac{1}{m}\right)$ and
${\cal{O}}(p^{10})$ relativistic corrections to potential and kinetic energy
terms have been added to the Hamiltonian. The screening potential employed is
solved by applying the gaussian wave function. The estimated masses are used to
construct the Regge trajectories, which help us in the association of some
newly observed states to $B$ and $B_s$ meson family. Overall, the results from
the present study are in fair agreement with available experimental and
theoretical studies.
| [
{
"created": "Tue, 4 Jan 2022 13:05:29 GMT",
"version": "v1"
},
{
"created": "Wed, 5 Jan 2022 04:44:24 GMT",
"version": "v2"
}
] | 2022-01-06 | [
[
"Patel",
"Vikas",
""
],
[
"Chaturvedi",
"Raghav",
""
],
[
"Rai",
"A. K.",
""
]
] | Inspired by the recent observations of $B$ and $B_s$ meson states at LHCb\cite{Aaij:2020hcw} we calculate the masses of ground, orbitally, and radially excited states. Also, we estimate the mixing parameters, decay constant, leptonic decay width, and corresponding branching ratios, as well as electromagnetic transition widths. ${\cal{O}}\left(\frac{1}{m}\right)$ and ${\cal{O}}(p^{10})$ relativistic corrections to potential and kinetic energy terms have been added to the Hamiltonian. The screening potential employed is solved by applying the gaussian wave function. The estimated masses are used to construct the Regge trajectories, which help us in the association of some newly observed states to $B$ and $B_s$ meson family. Overall, the results from the present study are in fair agreement with available experimental and theoretical studies. |
1506.04415 | Jacopo Ferretti | J. Ferretti and E. Santopinto | Open-flavor strong decays of open-charm and open-bottom mesons in the
$^3P_0$ model | null | Phys. Rev. D 97, 114020 (2018) | 10.1103/PhysRevD.97.114020 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We provide results for the open-flavor strong decays of open-charm ($D$ and
$D_{\rm s}$) and open-bottom ($B$, $B_{\rm s}$ and $B_{\rm c}$) mesons. The
decays are calculated in a modified version of the $^3P_0$ pair-creation model,
assuming harmonic oscillator wave functions. The spectra of open-charm and
open-bottom mesons used in the calculations are computed within Godfrey and
Isgur's relativized quark model. Quantum number assignments are also provided.
Our results are compared with the existing experimental data.
| [
{
"created": "Sun, 14 Jun 2015 16:21:53 GMT",
"version": "v1"
},
{
"created": "Thu, 16 Feb 2017 05:31:26 GMT",
"version": "v2"
},
{
"created": "Sat, 30 Dec 2017 08:52:07 GMT",
"version": "v3"
},
{
"created": "Wed, 20 Jun 2018 20:34:43 GMT",
"version": "v4"
}
] | 2018-06-22 | [
[
"Ferretti",
"J.",
""
],
[
"Santopinto",
"E.",
""
]
] | We provide results for the open-flavor strong decays of open-charm ($D$ and $D_{\rm s}$) and open-bottom ($B$, $B_{\rm s}$ and $B_{\rm c}$) mesons. The decays are calculated in a modified version of the $^3P_0$ pair-creation model, assuming harmonic oscillator wave functions. The spectra of open-charm and open-bottom mesons used in the calculations are computed within Godfrey and Isgur's relativized quark model. Quantum number assignments are also provided. Our results are compared with the existing experimental data. |
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